Excavation activity has begun at 509 Third Avenue in Murray Hill for what will become a 35-story mixed-use residential development. Situated at the corner of East 34th Street, the site has been cleared following the demolition of multiple five-story buildings that once occupied the property. Ismael Leyva Architects is the architect of record and Kevin Lalezarian under the Third and Thirty Four LLC is listed as the owner behind the applications for the 386-foot-tall structure, which will yield 229 units.