In reply to jasonpather:
For my mate's ...
Left home at 0400, drove to Snowdonia. Tryffan north ridge, Bristly Ridge, rest of the Glyders, and then down over Y Garn.
Pitched tents and had a huge gut busting mixed grill. Went around to Pen y Pass, up over Crib Goch to hit Snowdon summit at sunset. Watched a stunner of a sunset while enjoying a bottle of single malt. Rolled down the Pyg Track slowly and got back to the tents just after midnight!
Biggest cost was the fuel to get there and it was a fantastic stag do!!
For a train based suggestion...catch train to Torquay (Torre Station). Book Coasteering in Ansteys Cove (quite a few providers organise trips there). Plenty of accommodation in the town, especially cheap away from peak season. Biking to be done on Haldon Hills, Dartmoor etc, or kayaks/canoes can be hired in Exeter to complete the canal pub crawl....Prospect Inn, Double Locks, Turf Lock Inn!