Under a modern roof on the edge of the old town, the story of Saint Eulalia continues underground. The basilica built over her grave was the focus of one of the most important cults in Roman Hispania, and the excavations here show how the place grew over time: first a cemetery outside the walls, then a martyr's shrine in the fourth century, then a large church with additions, burials and a baptistery. The interpretation centre lets you walk around these layers on raised walkways, looking down at stone coffins, brick walls and mosaics, with panels that explain the stages. It is the sort of display where you have to slow down to work out what you are seeing.
Mérida was the capital of the Visigothic church in the south of Spain, and its bishops were powerful. The best known of them, Masona, who held the see in the late sixth century, is said to have founded a hospital for the poor and clashed with the Arian king, according to a chronicle written by a local cleric. Pilgrims came to Eulalia's tomb for centuries, and the shrine's fame crossed the Pyrenees, with churches in her name appearing well beyond Spain. In the Muslim period the city declined, but the cult never quite vanished.
The riding around Mérida is a mix of flat plain and gentle hills. West of the city, roads run toward the Portuguese border at Badajoz, with long straight sections through fields and olive groves, and to the north the hills begin to rise toward Cáceres and Trujillo, with more bends and a few good climbs. The road surfaces are mostly decent, but there can be gravel at junctions and farm tracks. Be aware of the afternoon sun and the strong wind on the open stretches. Spring and autumn are the best seasons, because the extremes of summer and winter are both unpleasant.
You are in a city of fifty-six thousand people, which means fuel, shops and cafes are close, and Calamonte, across the river, adds more. A carafe of local wine with a plate of cheese at a terrace in the evening is the classic ending. The air around the site smells of dust and old stone, and the quiet in the walkways is almost physical. Look for a seat in the shade at the entrance and let the place settle.