In 1825, London began the building of the first tunnel under a navigable channel: the Rotherhithe tunnel under the Thames. In 1869, it was integrated in the railway, then the underground railway network. The tunnel’s entrance was then closed to the public. The Brunel Museum has recently transformed this place, which descends 20 metres below ground, into a concert hall. The room can now hold 135 people. The concept of underground music takes on a whole new meaning in this case!