Team Building in Plymouth. Plymouth is a port city in Devon, southwest England. It’s known for its maritime heritage and historic Barbican district with narrow, cobbled streets. Sutton Harbour is home to the National Marine Aquarium, where sharks and rays glide in a deep tank. Also in the harbour are several marinas and a fish market, the Plymouth Fisheries. The Mayflower Steps are where the Pilgrim Fathers set sail for the New World in 1620.