When I tried to invite people to the park in the image I wanted to meet around the area where Babelsberger Strasse ends, anywhere within the red ellipse. As you can see, the park is a West-East band of green; I wasn't sure where exactly we would find a pick-nick spot but people should not look for us far away from a line formed by an imagined extension of Babelsberger Strasse through the park. In German I would say "[in] Höhe Babelsberger Strasse"; this is a use of "Höhe" which is not related to altitude. It is also used with respect to landmarks in a long road, like "the store is on main street [English term for "Höhe" here] of the fountain". It's not exactly "where the fountain is", that would be too specific.
With respect to suggestions in comments (thanks!): It is also not necessarily "near" the fountain because it could be on the other side of, say, the Champs Elysées. This as well as "at the end of" is in case of the pick-nick location too specific on the North-South axis (namely too North). The location may be farther away from the end of the street in the southern direction than westerly or easterly.
Is there a term I can use for a somewhat more vague location which is defined only in one dimension relative to a landmark?