The 301-foot-tall bell tower at the National Cathedral is the highest point in Washington, D.C. The Neo-Gothic tower offers sweeping views of the city below, and holds two sets of massive bells occupying three double-story floors in the upper section of the tower: two for the bells, and one for the ringers.

The “Peal Bells” dominate the top floor and were cast at the Whitechapel Bell Foundry, the same foundry that produced the Liberty Bell and the bell called Big Ben. In a room below, heavy ropes dangle from the ceiling and ring the bells when tugged. It takes a specially trained team of 10 people to operate the full set, with one person per rope. The ringers have decked out the rope room as a kind of club house, complete with a kitchenette, a small library, and several bell-themed trophies.

The second set of bells is located in an industrial-looking space beneath the ringer’s room. The bells hang from a huge rig of I-beams known in ringing circles as a Carillon. The ringer sits in a little booth at the center and plays the instrument using a simplified sort of keyboard. Outside his booth the wind blows in through towering windows that were left glassless to help the sound get out.

The huge bell tower was completed in 1963, but it’s designed in much the same way as a cathedral from the 1700s. The facade of Indiana limestone is held together with nothing more than mortar and gravity, and rests on an absolutely massive 48-foot-deep slab of unreinforced concrete.