Some areas of interest which have significant sections overlapping with the Strange things of the OOMlich:

Horror, paranormal, monsters
Abstract art, surrealism, psychedelic
Antiques, curiosity shops
Retro Sci-fi
Rock-and-roll, heavy metal
Goth, punk
Ripley's Believe It or Not
Abandoned places, junkyards, scrap, graffiti
Mediaeval bestiaries
Cultural arts of India and Mexico

Not everything in these areas of interest are OOMlich, but there are often OOMs to be found in them.