Pantheon AI: Inside Europe's Next Hyperscale Campus

With the announcement of a new Pantheon AI campus, a transatlantic investment group is spearheading a project set to become the largest investment in Croatian history.

Topusko, a small town in central Croatia near Zagreb, has only 945 residents and may seem like an unusual location for a hyperscale company to hedge its bets.

But in 2027, Pantheon AI will be situated there: a 310-acre hyperscale AI data centre and innovation campus worth EU€50bn, the equivalent to US$58bn.

Pantheon Atlas will be developing what the company claims to be among the largest private US investments into Europe.

The design of the facility will position Croatia as a regional hub for digital infrastructure, aligning with NVIDIA GW-Scale AI factory standards.

How does Pantheon AI address Europe’s data centre constraints?

The project focuses on a structural capacity gap across Europe’s data centre market.

Across Europe, established data centre hubs operate with vacancy rates below 8%. At the same time, delays in grid connections limit potential expansion.

In Central and Eastern Europe, electricity demand from data centres is projected to grow three to four times by 2035, yet the region is still lacking a gigawatt-scale facility optimised for AI.

Pantheon AI is addressing this gap with a design that integrates large-scale compute capacity above Tier IV availability, the highest level of fault tolerance and uptime in data centre design.

The campus will support up to 1 GW total capacity, with 800 MW allocated to IT load.

This scale will allow hyperscale operators to deploy high-density AI workloads that require both sustained power delivery and advanced cooling systems.

Jako Andabak, Founding Partner at PantheonAI, says: "Pantheon AI is a signal to the world that Croatia is open for the highest-calibre investment.

"This project is the culmination of years of work to bring world-class digital infrastructure to Croatia, and we have assembled the deep local expertise, grid relationships and regulatory groundwork required to meet demand for data centre capacity.”

The campus forms part of a wider transatlantic partnership that combines US investment with local technical and regulatory expertise.

This structure ensures access to grid infrastructure and planning approvals, both of which present challenges in European data centre expansion.

Power, connectivity and resilience at scale

Energy supply is at the core of the project’s design. Pantheon AI will place up to 5.2 GW of renewable energy onto Croatia’s national grid.

The site includes a 500 MW on-site solar plant operating behind the meter, so power is generated and consumed directly without relying on public transmission networks. This is alongside 8,000 MWh of battery storage to stabilise supply.

The project's transmission infrastructure will connect through four independent 400 kV lines, supporting both redundancy and capacity for Tier IV-level resilience.

Connectivity also underpins the campus, with four independent fibre routes linking the site across three major European Union corridors.

The GreenMed subsea cable aims to extend connectivity to Milan by 2028, with a network design that supports low-latency data transfer.

Ryan Rich, Managing Partner of PantheonAI, says: "We have assembled a transatlantic partnership to solve one of the most pressing challenges in global digital infrastructure: enabling hyperscale operators to meet AI-driven demand at scale.

"We have lined up the power, fiber, regulatory stability and institutional support to solve that problem in Europe, and we will establish Croatia and Central Europe as a premier destination for world-class digital infrastructure."

Strategic investment and regional impact

The project was announced at the Three Seas Initiative Summit in Dubrovnik, attended by 13 presidents and prime ministers alongside the US Secretary of Energy, Chris Wright.

Joshua Volz, Special Envoy for Global Energy Integration at the US Department of Energy, says: "The race to lead in artificial intelligence is global, and we are pleased to see American capital and investment expertise like Pantheon AI anchoring that leadership in allied, democratic nations.

"Critical infrastructure of this scale, built by the private sector responding to real market demand, is exactly how US interests and European security advance together.”

Construction of the EU€12bn (US$14bn) campus will begin in early 2027, with full operations expected by the first quarter of 2029.

The wider €50bn (US$58bn) investment total reflects additional spending by hyperscale tenants as they install computing equipment and supporting technology.

The site will have expansion capacity to 450 acres, sitting within 45 minutes of Zagreb and three nearby cities, providing access to a skilled workforce.

Once complete, the campus will support 1,500 permanent roles and 3,000 construction jobs.