The Laacher See: volcanic crater, circular walks and abbey

A lake that is a crater

The Laacher See looks peaceful. In fact it lies in what is left of one of the largest volcanic eruptions in central Europe.

Around 13,000 years ago the Laacher See volcano erupted. The ash cloud reached as far as Scandinavia and northern Italy, and the pumice layers of the Osteifel all date from that single event. What it left behind was a collapsed basin that filled with water.

The volcano is considered dormant, not extinct. Gas bubbles still rise on the south-eastern shore to this day — mofettes, carbon dioxide escaping from deep underground. Walk along the shore and you can see them in the shallows in several places. It is a quiet detail, but it stays with you.

The lake covers 3.3 square kilometres and is 51 metres deep at its deepest point. It has no natural outflow.

Two circular walks

Lakeside circuit (ML 2) — 8.4 km, around 2 hours Runs close to the water all the way round the lake. Largely flat and easy going, manageable with children too. The classic route, and the one where you see the mofettes.

Ridge circuit (ML 1) — 14.1 km, 3.5 to 4.5 hours, 270 metres of ascent Follows the crater rim high above, with views across the lake and far into the Osteifel. On the way you pass the Lydiaturm tower of 1927.

Both routes are waymarked and can be started from the car park by the abbey.

Maria Laach Abbey

The Benedictine abbey was founded in 1093 and is one of the best-preserved Romanesque buildings in Germany. Its six-towered abbey church is visible from almost every point on the lake.

Today the community numbers 25 monks. Abbot Mauritius Wilde has led the abbey since October 2025.

What you can visit:

Guided tours of the Jesuit library are charged for; the church itself is free.

The garden centre is worth a look even if churches are not your thing — it is a good deal bigger than you would expect.

Boat hire

From April to the end of October you can hire rowing boats and pedalos at the start of the lakeside circuit.

Swimming

Swimming is possible, but in one place only: the designated bathing area is on the campsite and can be reached only through it. It is shallow and well suited to children and non-swimmers, though you should expect water plants. The rest of the shore lies within a nature reserve.

If you want to swim safely, stay at the Riedener Waldsee — there it is officially designated and monitored by the authorities. See Swimming in the Riedener Waldsee.

What to combine it with

The Laacher See lies between Rieden and the Rhine — there are several routes there, and plenty to combine it with:

• Lava-Dome Mendig (about 8 km from the lake) — volcano museum and lava cellars, the same story continued underground
• Römerbergwerk Meurin (about 12 km) — the largest surviving tuff quarry north of the Alps
• Wingertsbergwand near Mendig — a wall of pumice up to 40 metres high, laid down by the eruption, freely accessible with information boards

All three belong to the Vulkanpark Osteifel and tell the same story from different angles.

Getting Here

Around nine kilometres from Rieden, about 15 minutes. There is parking at the abbey and at several points along the shore.

The lake makes a good first outing on the day you arrive — close enough to fit in, and big enough to fill half a day.