An in-person town hall will be held this week at the MetLife campus in South County about a proposed mixed-use development at the 100-acre site that would include two new subdivisions with more than 170 single-family houses, a 210-unit apartment building, nearly 8 acres of commercial development fronting Tesson Ferry Road and public spaces like a plaza and amphitheater. The land size and scope of the project between Tesson Ferry and Keller roads, called “Tesson Ridge,” makes the mixed-use project one of the largest developments in South County history — larger in size even than the roughly 47-acre Crestwood mall site, which is also the subject of a pending mixed-use redevelopment proposal.