At the heart of the city is the twin-towered cathedral (known as Catedral), which is where any tour of Guadalajara should begin. Construction started in 1558, but more than four centuries of remodeling, earthquakes and reconstruction have made it a blend of architectural styles including Gothic, Corinthian, Byzantine and neoclassical. The cathedral has stained-glass windows, painted ceilings, high vaults and 11 altars donated to the church in the early 1800s by the king of Spain. Don't miss Bartoleme Murillo's La Asuncion de la Virgin, painted in 1650, in the sacristy. Open daily. Free. Ave. Alcalde 17, Guadalajara. Phone 33-3614-3058.