Few people ride out of Barcelona expecting to find Gaudí in a mill village, but that is exactly what waits at Santa Coloma de Cervelló, a short hop up the Llobregat from Sant Boi. The Colònia Güell was a textile colony founded by the industrialist Eusebi Güell, who moved his cotton works out of the city in the 1890s and built housing, a school, shops and a theatre for the workers around the factory. He asked his friend Antoni Gaudí for a church. Gaudí spent about ten years on the design and its foundations, and when money and the Güell family's enthusiasm ran out around 1914, only the lower level had been finished. That crypt is what you come to see.
It is a strange, wonderful room. The columns lean like tired men, some of them rough basalt, some brick; the vaults are ribbed with brick in patterns that look improvised and are anything but. Gaudí worked out the forces with a hanging model of strings and little bags of shot, then turned the shape upside down, and you can feel that logic in the way the whole thing seems to grow rather than stand. Many ideas later used at the Sagrada Família were tested here first, which is why the crypt is part of the Gaudí World Heritage listing. The pews and the coloured glass, shaped like butterfly wings when the shutters open, are his too.
The colony itself rewards a slow walk. The red-brick workers' houses, the modernista villas of the managers and the old factory halls along the river make a tidy little town, quiet on weekdays and lively when the bar terraces fill on Sunday. Coffee and a sandwich are easy to find, and Santa Coloma and Sant Boi both have petrol stations on the way in or out.
As for the riding, be realistic: the approach is suburban, a knot of roundabouts, the B-23 and the old N-340 corridor, with industrial estates and plenty of vans. The reward comes once you head west or north. The hills of Collserola and the Ordal range are close, and the climb towards Cervelló and Corbera de Llobregat turns into proper twisting tarmac through pines and vineyards within twenty minutes. Early morning is best, before the heat and the traffic, and the light through the crypt windows is softest then anyway. Start or finish here and you get a hit of genius bookending a day of curves.