Built between 1622 and 1638, this fortress was, together with Mount Fortress, invaluable in fending off the attempted Dutch invasion of 1622. Inside the fortress stands Guia Chapel, built around 1622, and Guia Lighthouse, dating from 1865, the first modern lighthouse on the Chinese coast. Macao takes its co-ordinates from the exact location of the lighthouse. Guia Chapel was originally established by Clarist nuns, who resided at the site before establishing the Convent of St. Clare. In 1998 frescoes were uncovered inside Guia Chapel during routine conservation work. The chapel’s elaborate frescoes depict representations of both western and Chinese themes, displaying motifs of religious and mythological inspiration that are a perfect example of Macao’s multicultural dimension. Guia Fortress, along with the chapel and lighthouse are symbols of Macao’s maritime, military and missionary past. Guia Fortress has a trapezoidal plan covering an area of around 800 square metres. The lighthouse located within it, is a 15-metre-high tower with a diameter of 7 metres at the base narrowing upwards to 5 metres. At the top, there is a circular observation platform, where the lantern is installed. The light transmitter is accessed by a spiral flight of stairs inside. The tower has a simple rustic exterior, in keeping with Guia Chapel lying adjacent. The church has a simple façade, with a triangular pediment on pilasters finished in yellow rendering that contrasts with the unadorned white building. The chapel nave measures 16 by 4.7 metres, with thick bearing walls supporting the interior vaulting, further strengthened by buttresses running along the perimeter of the building. Inside, the sacristy is located on the left of the chancel and a small choir is located over the entrance. The roof is covered with traditional reddish ceramic tiles.