We end with the Pier - the only major attraction left. You may ask why they built long structures that stuck out in the ocean. What's the point? Wikipedia:

Santa Monica has had several piers; however, the current Santa Monica Pier is made up of two adjoining piers that long had separate owners. The long, narrow Municipal Pier opened September 9, 1909,  primarily to carry sewer pipes beyond the breakers.

Ah.