North Castle Ventures Launches 355 Main as a Destination Workplace; Announces Pre-Leasing Sellout
The adaptive reuse of 355 Main Street resulted in the complete pre-leasing of the second-level full-floor flagship suite.
North Castle Ventures has successfully launched the transformation of 355 Main Street, establishing the campus as a premier Destination Workplace in Westchester County. The radical adaptive reuse of the midcentury property has driven immediate market capture, resulting in the complete pre-leasing of the 2nd Level Full-Floor Flagship Suite.
Taking immediate occupancy this Fall is Alpha School, a pioneering educational network utilizing an AI-powered “2 Hour Learning” model to accelerate student mastery. Their deployment validates the campus’s capacity to seamlessly integrate advanced software architectures into physical real estate, proving the viability of high-density tech deployments in suburban commercial assets.
Referenced in this story
- 355 Main Street
- Node 1 workplace building within the Armonk Professional Center campus.
- North Castle Ventures
- Sponsor, owner and parent company of the NCV digital ecosystem, and owner of the Armonk Professional Center campus.
About North Castle Ventures
North Castle Ventures LLC is the sponsor and owner of the Armonk Professional Center portfolio at 355 and 357 Main Street in Armonk, New York, and steward of the AI-Native Office specification.
© 2026 North Castle Ventures LLC