One of the most interesting tours around London is the Rivers of London Livebet Tour, which takes in many of the historic rivers of the city, some of which have now ceased to exist or have been otherwise absorbed by the city. Another fascinating experience involves touring the underground, including visiting some of the famous lost and abandoned stations.
Paris
The Paris catacombs are another must see attraction. A product of the mass exhumation in the 18th century of the cemeteries that had started to unacceptably crowd within the city limits, the catacombs now hold the bones of some 6 million people. Originally merely piles of bones, the arrangements in the catacombs have evolved over the years into a rather grim form of artistry, and possibly the only place in the world where the hobby of femur arrangement is considered a socially acceptable form of self expression.
Obviously, guided tours are mandatory here as the possibility of becoming lost in a 300km long maze full of skulls is not the kind of memory you will want to associate with your European vacation.
