In the town of Chipiona, located in the province of Cádiz in Spain, you can actually find beaches with huge walls made of oyster stone called "Corrales", which were made by hand by Romans, but mostly used by Arabs for fishing. These walls create fishing ponds, which are huge traps that work with the tide. The idea is that fish get trapped inside of the walls when low tide approaches. Its effectiveness is higher during the tides with high degrees, because it is when more fish enter and it is easier to fish when at low tide.
The best time to fish in the “corral” is from January to May for the squid and from May to October for the rest of the fish. The fishing technique developed in these corrals is respectful of the natural environment and follows a series of norms of conservation.
It's really impressive to see it in person, and the sunsets in these beaches are simply magical. All photos on this post were taken by me with a Canon Powershot A2400.