Visit the north side of town for awesome views of the port served up with a side of history. Fort Gustav is one of three citadels constructed in the 17th century to protect the island's harbor against invasion. The fort is mostly in ruins today, but a few cannons remain, as well as a lighthouse that's still functioning (if not especially picturesque). Still, you'll enjoy the walk as you explore the surroundings. The area is rich in photo ops; signs indicating points of interest will keep you informed.