What is this tree that displays sycamore like characteristics but appears to be too small?
This is very likely a London planetree (Platanus × acerifolia), a hybrid species of Platanus often planted in cities.



 Source: Cuyamaca College 



 Source: Wikimedia 

The tree is a hybrid between Platanus orientalis and Platanus occidentalis (the sycamore tree), and has characteristics intermediate between the two species.


Smaller (heights of only 20-30 m vs 30-40+ m for parent species).
More deeply lobed leaf than P. occidentalis but less so than P. orientalis
Seed balls typically two per stem (one in P. occidentalis, 3-6 in P. orientalis)


Note: seed "balls" = aggregate of many small seed-like fruits called achenes

VERY OFTEN PLANTED IN URBAN AREAS  


Because it's very tolerant of atmospheric pollution and root compaction 



Description:


Leaves: alternate, simple, 3-5 lobes, maple-shaped, 10–20 cm long, 12–25 cm wide
Bark: pale grey-green (or brown), smooth and peeling (sometimes not peeling)