The centre of Amsterdam is quite compact and walkable, so it’s certainly possible to fit a lot into three days. Many of the major attractions are set close to Dam Square, so you could see the Royal Palace, Anne Frank House, and a couple of museums in one day. Boat cruises are an excellent way to see the city if you’re short on time, and hop-on-hop-off tours let you see the major attractions, without the walking, as well as giving expert commentary along the way.