Amsterdam's architecture is without a doubt a highlight of the city. The skinny brick buildings that line the city's canals were built tall and deep to avoid high property taxes which were calculated based on the width of one's house. Inside, dangerously steep staircases charm and eventually tire vacationers visiting town. Many of Amsterdam's buildings appear to be a bit off keel and while some locals suggest that these structures are slowly sinking into the marshland below, city historians claim that most of these buildings were purposely designed to lean in towards the canal so that home furnishings could be easily lifted to the upper floors without bumping into the side of the building.