[alison]

I am also on the lookout for accessible toilets in Brussels, but public toilets in general are few and far between (or just difficult to spot!).

Here is one that stood out  with a wheelchair mark near the square of Sainte-Catherine.  You need to put in a few coins to use it.

This area is a kilometre or so from the Grand Palace touristy area, but has lots of outdoor cafes and areas to stroll.

https://goo.gl/maps/2fHQxZHrMds