Seaside resorts are amazing for a Culture Victory. You can get a Culture Victory with minimal investment in great works.
Seaside resorts can only be built on flat, coastal plains, grassland, or desert tiles with a minimum appeal of 4. Once built, they provide double the tile's appeal in tourism. The way to use them is a) build the Eiffel Tower, which gives +2 appeal to all your tiles, and b) build the Christo Redentor, which makes your resorts provide quadruple the tile's appeal in tourism instead. So each resort then provides a minimum of 16 tourism.
You can expand the number of places you can build coastal resorts by planting a bunch of woods one tile off the coast. Woods grant +1 appeal to adjacent tiles. You can also plant woods next to coastal resorts you've already built, and they'll start generating 4 more tourism than they did before.
Seaside Resorts must be within 3 tiles of a city center or they won't generate any tourism, but they do not have to be worked by a citizen to generate tourism. So you could, in the late game, find an unclaimed strip of coast, settle a 1 population city, buy a few coastal tiles, and place 5 or 6 coastal resorts. If you have the right wonders, that city will immediately generate 100+ tourism.