In the upper town of Thessaloniki, just above the busy streets of Sykiés, stands the Church of Saint Catherine, a late Byzantine building of the thirteenth or fourteenth century, with brick and stone patterns in its walls and a cluster of domes and apses that give it a lively outline. It is dedicated to Saint Catherine of Alexandria, who was said to have been tortured on a wheel for her faith, and the cult was strong in the eastern Mediterranean. The church was originally larger and had a covered walkway, and like its neighbours it spent centuries as a mosque after the Ottoman conquest. Today it is a church again, a quiet place among the houses.
The building is typical of what archaeologists call the cross-in-square type, but with an ambulatory around three sides, which is unusual, and some people link it to monastic patterns elsewhere in the empire. Its walls have the decoration of brick set in zigzag and herringbone, the feature the Thessaloniki builders of that age loved. Inside, the frescoes are mostly faded, but the proportions are fine, with a sense of space greater than you expect from the outside.
Riding to it is an urban affair. The streets are narrow, hilly and often one-way, with a mixture of old and new houses and small gardens. Cars park on both sides, so a motorbike is easier, but you need patience for the maze, and a paper map is no less useful than a phone in the shadow of tall buildings. In summer the heat can bounce off the stone, and in winter the streets can be wet and slippery. Early morning and evening are the pleasantest times to visit, with fewer people and softer light.
Sykiés and Ágios Pávlos have fuel stations along the main roads, and plenty of grocery shops, bakeries and little restaurants where you can get a decent grilled meat dish for lunch. The ones off the tourist routes are often best, with handwritten menus and big portions. Greek coffee is served in a small cup with the grounds at the bottom, so do not drink to the last sip. The old walls of the upper town are a short climb above the church, with views over the red roofs and the sea to the south.