Basel used to have a town wall in the medieval ages. It had seven doors, and until the 19th century, Basel was well protected. Every night, the doors would be closed. If you wanted to come in after that, you had to do it through a special small side door (the needle hole) and would have to pay a fine as well as be registered.
Because the town grew too big, they finally tore down the walls and filled up the ditches.
From these seven doors, only three persist. They are the St. Alban Gate, the St. Johann Gate, and the Spalen Gate.
The St. Alban Gate in the picture is 32m high. It was the southern gate and a way to get to the Cloister settlement in the St. Alban Valley.
The Cluniazenser Cloister was founded in 1083. The romantic church of St. Alban belonged to it, too (and can also be visited here). The monks also made an artificial pond and two canals to the Rhine so they could power some mills.
The surroundings of the gate are wonderful pieces of the old Basel, with its well-maintained and renovated buildings. Just have a stroll around.