Thirlmere

Where is Thirlmere?

Thirlmere near Keswick, in the Lake District. Zoom and pan to explore — or see all the Lake District lakes & waters on one map.

Why can't you swim in Thirlmere?

Plainly: Thirlmere is an active drinking-water reservoir, and United Utilities does not allow swimming or paddleboarding on it (or on its other reservoirs) — a policy tightened after drownings, because reservoir water is cold, deep and has hidden hazards (steep underwater sides, submerged structures, sudden cold). So there's no swimming, no SUP and no open-water bathing here.

What you can do is walk — the shore circuit and the fells — and that's the real reason to come. (For a proper swim nearby, the natural lakes are the place: see Derwentwater or, for an allowed wild swim, Crummock Water.)

Helvellyn from Thirlmere — the gentler way up

Thirlmere is the western approach to Helvellyn, England's third-highest mountain, and it's the easiest way to the summit. From the Swirls car park (or Wythburn, by the church) on the A591, a steady, well-made path climbs directly to the top — a straightforward up-and-down with a big reward and, crucially, no Striding Edge. That makes it the sensible choice in poor visibility, in winter without scrambling kit, or simply if exposure isn't for you.

Contrast that with the famous eastern approach from Glenridding over the Striding Edge and Swirral Edge — spectacular, but a serious, exposed scramble. Same mountain, very different days. Either way, check the forecast: Helvellyn's plateau is a wild place in cloud.

The circular walk & road — is it open?

Yes — you can walk a full circuit of Thirlmere (roughly 9 miles), using the single-track West Road and the lakeshore footpath on the western side, with the A591 along the east. A section of the West Road and lakeshore path beneath Rough Crag was closed for safety from 2021, but United Utilities completed the crag stabilisation and the route reopened in 2024, so the full circular walk is once again accessible. Closures here have a habit of recurring after storms, though, so it's worth a quick check of the United Utilities Thirlmere page for any current restriction before you set out.

The drowned hamlets, the forest & the crags

Before the dam, Thirlmere was two smaller lakes with the hamlets of Wythburn and Armboth in the valley; the dam of the 1890s flooded them, and conifers were planted from 1907 to protect the water — giving Thirlmere its distinctive dark, forested shores (now gradually being diversified with native trees). A few older things survive: the tiny Wythburn Church still stands by the A591; Raven Crag rises dramatically above the northern end (a short, steep climb to a superb view down the lake); and Castle Rock of Triermain, the crag that Walter Scott wove into legend, stands at the valley's north. There's also a popular armchair-shaped Armboth shore and the famous "floating" stepping experiences of the forest trails.

Getting there & parking

The A591 — the main Keswick–Grasmere–Windermere road — runs the full length of Thirlmere's eastern shore, so it's very easy to reach (and the 555 bus between Keswick and Windermere passes right by). There are car parks at Swirls and Wythburn (for Helvellyn), at Armboth and the dam on the west side, and laybys along the way. Keswick, a few miles north, is the nearest town for everything else.

Fells & walks near Thirlmere

• Raven Crag 461 m · 1.2 km
• High Seat 609 m · 2.2 km
• High Tove 515 m · 2.3 km
• Armboth Fell (Armboth Fell South Top) 475 m · 2.4 km
• Bleaberry Fell 590 m · 3.0 km
• White Side 863 m · 3.1 km

Straight-line distances from the centre of Thirlmere — the nearest summits with a full guide on this site.

All walks by Thirlmere → — every route and fell within about 5 km, ranked, with today’s conditions.

Where to stay & practical

Thirlmere itself is quiet, with little right on the water — most people base themselves in Keswick to the north or Grasmere to the south, both a short drive away and full of accommodation. It's good, peaceful walking and forest-cycling country, but remember the reservoir rules: no swimming, and check current path/road closures.

Easy day trips take in Keswick and Derwentwater to the north, Grasmere and the central fells to the south, and of course Helvellyn on the doorstep. We don't publish live reservoir levels or guarantee the circular route is open — check United Utilities for the current picture before you travel.

Events & festivals

Planning a trip around a show or festival? See our Lake District events & festivals guide for what's on near Thirlmere — traditional Lakeland sports, agricultural shows and seasonal events, month by month.