While Windermere pulls the crowds, England's most remarkable lake sits quietly at the western edge of the Lake District. Wast Water, in Cumbria's Wasdale Valley, holds two national records: it's the deepest lake in England at roughly 258 feet, and it has the country's cleanest lake water based on phosphorus data — a sharp contrast to busier neighbours like Windermere, which have struggled with pollution and bacteria in recent years.

By surface area, Wast Water is modest — just over a square mile, about 3 miles long and half a mile wide, only ninth-largest in the park. But glacial ice carved it far deeper than any other English lake, plunging to depths that may exceed those of the nearby Irish Sea. It's not the UK's deepest (that's Scotland's Loch Morar, over 1,000 feet down), but the combination of record depth and record cleanliness is unique in England.

The setting explains a lot. Wasdale is a dramatic valley of ancient volcanic rock, ringed by peaks including 3,210-foot Scafell Pike, England's highest mountain, and the craggy face of Illgill Head. Mists roll through regularly, and the whole scene feels wilder and more remote than the honey-pot lakes to the east.

Getting there takes commitment: it's about an hour and a half by road from Windermere, the park's main hub. Once there, options range from gentle shoreline strolls near the roadside parking at Wasdale Head and along Lakeside Road, to the demanding 8-mile Wast Water Circular around the entire shore — a mix of flat paths and rough, rocky ground with uninterrupted valley views. Experienced hikers can tack on the 4.2-mile Nether Wasdale and Wast Water Trail through woods and farmland, or a tougher 9-mile route up Illgill Head and Whin Rigg.

On the water, the clarity matters. Cold-water swimmers get about as pure an immersion as the UK offers, paddlers can explore the lake at a gentler pace, and divers have one of Britain's most intriguing freshwater dive sites thanks to those extraordinary depths.

For travellers, the appeal is simple: this is the Lake District without the queues. Wasdale Head, less than two miles from the shore, is a small village with real walking heritage — and the Wasdale Head Inn is the classic spot to end a day on the fells. If you've done Windermere and found it overwhelming, Wast Water is the antidote.