Motivation behind booking sites listing too many cities

What could it be the motivation behind some travel websites that dedicates a huge section to list all cities they are present?

Here are some examples:

• booking.com
• tripadvisor.com.br
• trivago.com.br

I'm assuming its for SEO reasons, because they far from the top and are clearly not readable?

Or is there any chance users read all those cities and really click on them?

Any thoughts?