Visualize database schema

Hello,

Apologies if this question has been asked before, but I couldn't come up with a decent solution...

Can anyone advice about a tool to visualize a database schema? Ideally, I would like something that takes the SQL definition of a schema or database (essentially the output of pg_dump) and produces a graphical representation of the tables, constraints and indexes which can be moved around for ease of visualization (something like the "Graphical query builder" that comes with pgAdmin =>1.14).
I don't care (and don't want) to modify or query the database with such tool, I just want to visualize it. (In fact, I tried to use pgAdmin for this but the graphical queries can only be saved as images and so they cannot be reloaded).

Thanks!

Dario