The Prime Minister yesterday took a tour around a busy railway station which doesn't yet exist.
Mr Key slipped on a virtual reality headset for a walk around Aotea Station - one of the proposed underground stops for Auckland's $2.5 billion City Rail Link.
The station is projected to handle around 12,000 people in peak hours and be one of the busiest hubs on the network.
Describing the visit to a downtown control room as a chance to grasp the complexity and potential of a crucial venture, Mr Key stressed the importance of making sure one of the biggest engineering missions in Kiwi history gets a "successful execution".
"This is something that's been talked about for decades. It's exciting, but something you've got to get right," Mr Key told the Weekend Herald. "The successful execution of the plan will allow it to be delivered on the broad budget of $2.5 billion to $3 billion. If you don't do that, everyone can see how challenging that might be.