De or het modderkuil?

The correct Dutch article is:

de modderkuil

How to use modderkuil

the modderkuilde modderkuil
this modderkuildeze modderkuil
that modderkuildie modderkuil
our modderkuilonze modderkuil
your modderkuiljouw modderkuil
every modderkuilelke modderkuil
which modderkuil?welke modderkuil?
a big modderkuil / the big modderkuileen grote modderkuil, de grote modderkuil