古城公园 (Gucheng Park) is a quaint park located a block down from Shanghai's traditional Yu Gardens. The area is surprisingly chill compared to its bustling neighbors, featuring nothing more than some lawns, a teahouse, and a stream that drains into the Huangpu, across which the modern Lujiazui stands in stark contrast with Puxi's rich tapestry.
A photographer friend of mine once showed me a shot of the tree at this spot with Shanghai Center directly behind, as if China's tallest building was its stem. I have never excelled at photography (or any form of art for that matter), but it's a gorgeous spot nonetheless, making it host for this cache.
BYOP and good luck!