CoreSite Atlanta (AT1)
55 Marietta Street NW, Atlanta, GA, 30303, US
AT1 is CoreSite's 62,000-plus square feet inside 55 Marietta Street, the 21-story building that has served as Atlanta's principal carrier hotel for decades and which CoreSite occupies as a tenant rather than an owner. CoreSite operates one of the building's two meet-me rooms, and 70 networks across four exchanges are reachable on-net from its suites - a density it did not build but can sell access to, with 22 carriers present in the building overall. Within its own space CoreSite offers N and 2N options on UPS, PDU and RPP, N generators, and N+1 mechanical redundancy through variable-speed CRACs, pumps, heat rejection units and cooling towers. Cloud on-ramps reach AWS, Azure, Google Cloud, Oracle and IBM. The building changed hands in December 2025, when RadiusDC acquired it and began adding 8 MW of site capacity.
Facility Specifications
Site information
- Colocation space
- 62,000+ sq ft of CoreSite space within a 403,000 sq ft, 21-story building
- Uptime SLA
- 100% uptime SLA
Power & cooling
- Redundancy
- N generators; N and 2N options across UPS, PDU and RPP; N+1 mechanical, pumps, heat rejection units and cooling towers
- Cooling
- Variable-speed CRACs with humidification control; N+1 pumps, heat rejection units and cooling towers
Compliance
Platforms & amenities
- Platforms & services
- Cabinets, cages and private suites; Open Cloud Exchange and CoreSite Interconnect Gateway; 24x7x365 remote hands
- Amenities
- WiFi; secure parking; kitchen and TVs. Key card and biometric access, perimeter and interior IP-DVR, 24x7x365 security staff.
Network ecosystem — 71 carriers on-net
Notable: Cogent Communications (AS174) · GTT Communications (AS3257) · Zayo (AS6461) · Hurricane Electric (AS6939)
Show 41 more carriers
Cloud on-ramps
70 networks and 4 exchanges on-net, with 22 carriers present in the building. CoreSite operates one of the building's two meet-me rooms. AWS Direct Connect, Azure ExpressRoute, Google Cloud Interconnect, Oracle Cloud Infrastructure and IBM Cloud via Open Cloud Exchange; Any2Exchange peering.