阅读下列短文，根据短文内容填空。在未给提示词的空白处仅填写1个适当的单词，在给出提示词的空白处用括号内所给词的正确形式填空。

Once upon a time, lighthouses, 【小题1】 (build) to help guide ships away from dangerous rocks and reefs, 【小题2】 (locate) in wild, remote areas. Today, with automatic lighting that can guide ships at sea, the lighthouse is a thing of the past. Still, many lighthouses throughout the world have been preserved as 【小题3】 (museum) or important buildings. Some have even been turned into restaurants or hotels. They are places for people to visit and to go back in time.