Shoreham Fort

The squat brick pentagon sits right on the shingle beach west of Lancing, impossible to miss if you're walking the Sussex coast. Shoreham Fort dates to the 1850s, built when the Victorians got jumpy about a potential French invasion, and it's one of the best-preserved examples of that paranoid era of coastal defence you'll find along the south coast.

What you're actually getting is a working military fort - still used by the MOD, which means access isn't always straightforward and opening hours are irregular at best. When you can get in, the brick casemates and gun emplacements give a proper sense of how these fortifications were meant to operate. The location is the real draw though. Standing on the ramparts, you've got unobstructed views across the Shoreham gap to the Downs inland and along the pebble beach in both directions. On a clear day it's genuinely striking.

History buffs will spend a couple of hours exploring the structure and its 1850s purpose. Families with younger kids might find half an hour about right before they get restless - there's not masses to do beyond poking around the chambers. Walkers doing the coastal path should factor it in as a natural stopping point. The nearby caravan parks at Eastern Sands and Beach Park put you within spitting distance if you're basing yourself here for a longer break. Worth ringing ahead before you visit though - the fort's accessibility is hit-and-miss depending on military schedules.