while the northern side as two double and one quadruple mullioned windows. The bell tower, standing at 59 m, was mostly built in 1230–1239, although the floors above the second one were completed only in the 14th century under bishop Giacomo Tura Scottini. As is typical in Romanesque structures, the openings (in the shape of mullioned windows) become wider in the upper floors. The ground floor of the bell tower has an internal, ogival arcade creating a passage under it. The bell tower was completely dismantled and rebuilt in the 1950s to avoid it falling down. Interior The church plan has a nave and two aisles, separated by double columns that support two side matronaei. The aisles have cross vaulted ceilings, while the nave has nude trusses. The transept has also similar trusses. The interior has lost much of its decoration, leading to the current largely bare appearance. In particular, the restoration in 1939-1942 mostly left only the medieval elements, removing later additions such as the painted wooden ceiling of the nave and the transept. Only part of the original mosaics of the pavement, inspired by those of the Otranto Cathedral, remain in the presbytery area. These include scenes such as the allegory of Alexander the Great flying to heaven (see below) and the original sin episode with Adam and Eve. The lower church, located under the main pavement, is divided into two main spaces: the Crypt of St. Nicholas, housing the saint's relics, and that of St. Mary. The lower church has a similar plan that the upper one and has Romanesque-style capitals. A small stairs leads to the hypogeum of St. Leucius, located below the sea level and decorated with frescoes in poor state of preservation. Flying Alexander A medieval legend in the Alexander romance had Alexander, wishing to see the whole world, first descending into the depths of the ocean in a sort of diving bell, then wanting to see the view from above. To do this he harnessed two large birds, or griffins in other versions, with a seat for him between them. To entice them to keep flying higher he placed meat on two skewers which he held above their heads. This was quite commonly depicted in several medieval cultures, from Europe to Persia, where it may reflect earlier legends or iconographies. Sometimes the beasts are not shown, just the king holding two sticks with