During the 1850s numerous maple trees were planted along Indiana and Michigan avenues in the city by local resident Sebastian Lay. Subsequently, La Porte became known as the "Maple City". Today, Indiana and Michigan Avenues comprise a historic district in the city, containing many homes and other structures of architectural and historical interest. Between 1892 and 1894, the third and current LaPorte county courthouse was erected at a cost of $300,000. The structure is built of red sandstone from Lake Superior, shipped via boat to Michigan City and then by rail to La Porte. The courthouse is considered to be one of La Porte's best known structures. In 2007 the exterior of the building was extensively restored at a cost of $2.9 million.