Okay, in visiting and blogging on all 108 St. Louis parks I've come across another mystery. The city website lists Tambo Park, a 1 acre park at Rutger and Ohio Avenues in the Gate District neighborhood as being placed into ordinance in 1985.
Google Maps has it pegged here:
This one is hard to get to and is only accessible from an alley between Caroline which is butchered mid-block and Rutger Street. The street grid has been substantially mangled in this part of the city, so it is really hard to get around in a vehicle. Once I finally found this place, all that is visible is this:
What can only be described as...a patch of mowed grass/weeds. The mystery continues as per city records from fiscal year 2012. There was $160,000 in improvements ear marked for Tambo Park:
TAMBO PARK PLAYGROUND RENOVATION $100,000
REPAIR MULTI-PURPOSE COURT $45,000
REPLACE PARK BENCHES $15,000
Here's my source. As you can see, there is no playground, multi-purpose court nor park benches. So this one is a bona fide mystery.
This park doesn't appear to exist in real life, only on Google maps and the city website...