Arrive today in London and proceed to the historic coastal town of Portsmouth to embark National Geographic Explorer. (D)

Be on deck this morning as we make a dramatic entry into the River Dart. Dartmouth has a great seafaring history. We stroll along the quaint waterfront, observing many fine old buildings that recall its nautical past. (B,L,D)

On the island of Tresco we visit the fabulous Tresco Abbey Gardens. The Gulf Stream allows an astounding variety of subtropical plants to flourish at these northern latitudes, and numerous birds, including shearwaters and sandpipers, are often seen here. (B,L,D)

Today we explore the roots of Celtic Christianity. We cruise slowly by Skellig Michael to view the beehive huts of a Celtic Christian monastery, built five hundred feet high atop the island in the sixth century. A half-mile distant is rocky Little Skellig, whose white spires reveal is as a favorite roost for seabirds. Go ashore at the beautiful Dingle Peninsula. Walk through the charming village of Dingle, sample an Irish coffee and browse the shops for woolens. (B,L,D)