Flanked by a historic cemetery and a lavishly ornamented 20C basilica, San Francisco's oldest extant structure serves as a distinct reminder of the city's Spanish heritage and a repository of early European history.The sixth mission in the Alta California chain was first established in 1776 two blocks east of its present site. A nearby lake named for Our Lady of Sorrows (Nuestra Senora de los Dolores) gave the mission its centuries-old nickname, Mission Dolores. A remarkably sturdy structure, the chapel, completed in 1791, has survived major earthquakes in 1868, 1906 and 1989 as well as abandonment and neglect. Cement stucco covers 4ft-thick adobe walls, while amber-colored windows bathe the interior in warm light. The ornate, hand-carved reredos and side altars were imported from Mexico in 1780, and bronze bells occupying niches high in the chapel's front exterior facade were brought as gifts in 1792, 1795 and 1797. The remarkable, multicolored motifs painted on the high, beamed ceiling are patterned after Ohlone basket designs. A narrow passage north of the chapel contains a splendid diorama of the mission as it appeared in 1799. The mission's small museum houses shards and shreds of artifacts discovered during restorations, as well as baptismal records and vestments dating from the colonial period. On the south side extends a tranquil cemetery; here, amid verdant, varied plantings, are buried many of San Francisco's early leaders.