SeaTV · Greece · Dodecanese Islands · Nisyros Island
Nisyros Island — Active Volcano, Stefanos Crater & Two Small Ports
A small round volcanic island ~8 NM SE of Kos with an active volcano you can walk into. Two mooring options: Port of Palon on the NE coast (small fishing harbour, good shelter, 30 berths, max LOA 12 m) and Mandraki Port on the NW (small, open NE, calm-weather visit only). Rent a car early in the morning to reach the Stefanos Crater before the heat, walk into the caldera with active fumaroles and bubbling sulphur, and visit the cliffside village of Nikia for the panoramic view back into the volcano.
Nisyros is a small round volcanic island about 8 nautical miles SE of Kos — one of Greece’s youngest active volcanoes and one of the most geologically distinctive islands in the Aegean. The whole island is essentially a single volcanic structure, with the Lakki caldera at its centre containing the active Stefanos Crater · 260 m wide, 30 m deep, with steaming fumaroles and bubbling sulphur deposits that you can walk down into. Two small ports serve sailors: Mandraki (the historic capital) on the NW and Palon (the practical fishing-port option) on the NE coast.
⚠ Reality check:
→ Reef N of Palon marina · ~100 m offshore · plot before approach
→ Palon entrance depths only 2.2-2.5 m · keep near the breakwater
→ Submarine cables E of Mandraki · anchorage + fishing prohibited
→ Mandraki Port open NE · calm weather only
→ No mooring lines at Palon · drop your own anchor
→ Volcano is HOT · visit early morning or twilight only
⚓ Nisyros at a Glance
Position
~8 NM SE of Kos
Geology
Active volcano · Stefanos Crater
Last eruption
1888 (still seismically active)
Mooring options
Palon (NE) + Mandraki (NW)
Population
~1,000 residents
Ferry
Daily Mandraki ↔ Kos in season
⚓ 1. Port of Palon — The Practical Fishing Harbour
Position · 36°37′.15N · 27°10′.25E · 30 Berths · Max LOA 12m
Port of Palon
Position: Small fishing port with good shelter located 2 NM east of Mandraki on the NE coast.
Berths: 30 · drop anchor and dock to N or S quay.
Max draft: 2-2.5 m · entrance the same · ⚠ keep near the breakwater on entry.
Max LOA: 12 m · this is a small fishing port · larger yachts won’t fit.
Bottom: Mud, sand, and rocks · reasonable holding · check the set.
⚠ NO mooring lines: Drop your own bow anchor · don’t expect lazylines.
⚠ Reef N of marina ~100 m: Plot it before approach · don’t sail over it.
⚠ Shallow areas: Be careful of shallows around the port · slow approach.
Facilities: Water + electricity at most berths · fuel by mini-tanker · showers at the end of the pier near the car rental · small shops + restaurants around the marina · this is the practical Nisyros base for sailors.
⚓ 2. Mandraki Port — The Capital, Calm-Weather Only
NW Coast · Small + Limited Space · Calm Weather Only
Mandraki Port
Position: NW coast of Nisyros · the historic capital town · the port at the edge of the village.
Reality: Small · space is limited · open to the NE. In calm weather it’s well worth a visit · in any non-calm conditions move to Palon.
⚠ Submarine cables east of port: Anchorage and fishing on both sides are prohibited · plot the cable line on the chartplotter.
⚠ Ferry traffic: Daily ferry to Kos in season comes in and out of the port · be alert and give way · monitor VHF Ch 16 + 12.
Best for: Day-stop in settled summer weather + lunch in the historic town. Use Palon for overnight or any non-perfect conditions.
The Volcano — Stefanos Crater & Lakki Caldera
An Active Volcano You Can Walk Into
The whole island of Nisyros is essentially a single volcanic structure · the Lakki caldera at its centre is a wide collapsed-crater zone, and the Stefanos Crater within it is the main active feature: 260 metres wide, 30 metres deep, with active fumaroles, hot springs, and bubbling sulphur deposits. You can walk down into the crater on a marked path · the floor is yellow-encrusted with sulphur, hisses with steam vents, and gives off a heavy sulphur smell. One of very few active-volcano experiences accessible by sailing yacht in the Mediterranean.
Last Eruption — 1888
Nisyros’s last major eruption was in 1888 · the volcano is still seismically active and the Greek monitoring authorities track it continuously. The Mediterranean Volcanic Arc continues through Santorini, Methana, and Nisyros · all share the same tectonic origin.
Mythological Origin — Poseidon & Polybotes
Greek mythology gives Nisyros a creation story: during the Gigantomachy (the war between gods and giants), the giant Polybotes fled the battlefield. Poseidon tore a piece off Kos and threw it at the giant, burying him beneath it · the piece became Nisyros and the rumblings of the volcano are Polybotes still trying to escape from underneath. Whatever you make of the myth, the geological reality (Nisyros and Kos sit on the same volcanic line) does have an interesting echo.
Visit Strategy — Early Morning or Twilight
Rent a car at Palon · drive to the volcano · go early in the morning or at twilight because the crater area is HOT (both ambient air and the volcanic heat from the floor). Allow 2-3 hours · the marked walk down into the crater takes 30-45 minutes plus exploration time.
The Villages of Nisyros
Mandraki — The Capital
The historic capital on the NW coast · whitewashed houses · the Panagia Spiliani Monastery (the “Virgin Mary of the Cave”) inside an 11th-century cave · the medieval Knights of St John castle on the hilltop · the small village square with tavernas. Walking distance from the port.
Nikia — The Cliffside Village
Nikia sits on the rim of the Lakki caldera at ~400 m elevation · a small whitewashed village with an unusual mosaic central square laid out as concentric circles · the panoramic view directly down into the volcano is the unique feature. Drive up after the volcano visit · stop for lunch with the caldera view.
Hot Springs at Mandraki
The volcanic activity that drives Stefanos Crater also feeds hot springs in the Mandraki area · used historically for therapeutic bathing · still accessible. Combined with the Knights’ castle and the cave monastery, Mandraki gives you a layered shore visit even in the calm-weather day-stop format.
Wind & Shelter
Palon — good shelter: The fishing-port basin is well sheltered · the practical overnight stop on Nisyros · works in moderate Meltemi.
⚠ Mandraki — calm weather only: Open to the NE · any NE wind component (which the Meltemi brings in the form of N-NE in this area) sends waves into the port · day-visit only in settled conditions.
Best season: May-October · September-October peak quality (cooler for the volcano walk!).
Pro Tips for Nisyros
Default to Palon for overnight. Good shelter, 30 berths, services, car rental at the pier · Mandraki is for day-visits only.
Plot the reef and the cable. Reef ~100 m N of Palon marina · submarine cables E of Mandraki · plot both before navigating in the area.
Visit the volcano early morning. The crater is HOT — both ambient and volcanic heat from the floor · 7-9 AM is optimum · 11 AM onwards is uncomfortable in summer.
Combine volcano + Nikia in one trip. Drive up to Stefanos Crater first, walk in, drive up to Nikia for lunch with the caldera view, then descend back to Palon · half-day shore excursion.
Bring sturdy shoes and water. The crater walk is on volcanic rock and ash · slippery in places · the ambient heat means you need water · don’t go in flip-flops.
Pair with Kardamena (Kos). Kardamena port has the daily ferry to Nisyros · alternative to sailing · or sail to Nisyros directly and use the ferry as a contingency. See Kardamena Kos.
Visit the Panagia Spiliani Monastery in Mandraki. 11th-century cave monastery · unusual setting · combined with the Knights’ castle on the hilltop above · a layered Mandraki shore visit.
Routes from Nisyros
N to Kos: ~8 NM N · ferry connection from Mandraki. See Mandraki Kos · Kardamena.
SE to Tilos: ~10-15 NM SE. See Tilos Island · Eristos Bay.
NW to Astypalaia: The crossover into the eastern Cyclades.
Dodecanese full route: See Dodecanese — Our Route.
Emergency Numbers — Nisyros
European Emergency: 112
Greek Coastguard: 108
Coastguard Distress (VHF Ch. 16): Universal
Nisyros Port Authority: +30 22420 31222
Watch the SeaTV Visual Pilot Video
Drone passes the round volcanic shape of Nisyros from the air, the Stefanos Crater with its yellow-encrusted floor and steaming fumaroles, the cliffside village of Nikia on the caldera rim, the historic capital Mandraki on the NW coast with the Knights’ castle on the hilltop, and the practical fishing port of Palon on the NE with its 30-berth quay. The active-volcano-island experience captured in one visual pilot. Free for members.
Related SeaTV Pages
Adjacent — Kos & Tilos
→ Kardamena Kos · daily ferry to Nisyros
Sailing to Nisyros?
Active volcano you can walk into · Stefanos Crater 260 m wide · Lakki caldera · two ports (Palon practical · Mandraki day-visit) · early-morning volcano visits only.
→ Kardamena ferry hub · Tilos SE · Kos N
“Nisyros is a small round volcanic island eight nautical miles southeast of Kos with one of the very few active volcanoes you can walk into in the Mediterranean — a 260-metre-wide crater floor encrusted with yellow sulphur, steaming fumaroles, and bubbling hot deposits in the middle of the Lakki caldera. Berth at Palon on the NE coast (small fishing harbour, good shelter, thirty berths, max LOA twelve metres), rent a car early in the morning before the heat hits, walk down into Stefanos Crater, drive up to Nikia for lunch with the caldera view, and the cave monastery and Knights’ castle in Mandraki finish the cultural picture. Watch the reef north of Palon, the submarine cables east of Mandraki, and the ferry traffic, and the volcano-island experience opens up.”
— SeaTV Visual Pilot · Dodecanese Edition
