De or het middagwandeling?

The correct Dutch article is:

de middagwandeling

Rule Words ending in -ing: almost always de. See the rule

How to use middagwandeling

the middagwandelingde middagwandeling
this middagwandelingdeze middagwandeling
that middagwandelingdie middagwandeling
our middagwandelingonze middagwandeling
your middagwandelingjouw middagwandeling
every middagwandelingelke middagwandeling
which middagwandeling?welke middagwandeling?
a big middagwandeling / the big middagwandelingeen grote middagwandeling, de grote middagwandeling