Edinburgh Castle

Hoisted high on the craggy Castle Hill, almost as if it's monitoring the city below, Edinburgh Castle is one of the city's must-see attractions. Inside its blackened stone walls are the Honours (or crown jewels) of Scotland, Queen Mary's Apartments, the Great Hall and the infamous Mons Meg cannon.

Some travelers express disappointment in the castle's high price of admission, saying they enjoyed the free vistas on the outside rather than the expensive sightseeing on the inside. But others say their pounds were well-spent. One TripAdvisor traveler recommends wearing comfortable shoes (there's lots of walking) and planning your visit around the 1 p.m. (on weekdays) gun firing.