Database structure and relation viewer/editor

Dear PostgreSQL support,

I couldn't find any free tool or way to graphically view and or edit my
PostgreSQL database structure (tables and relations) like the tool
available in MS Access.

Does this exist ?
If yes, How to proceed ?

PS.: I am using PostgreSQL under Suze Linux 10.2 and use pgAdminIII to
manage it (but pgAdminIII apparently doesn't offer any graphical view of
the database structure).

Thanks in adavnace for your help

Best Regards

Cédric