Nor is there any sea, nor rivers, for an alternative form of transport. The Vatican City is, in fact, in the centre of Rome. And it is one of the few countries where access is almost exclusively on foot. That said, entrance is free, up to a point, given its interest as a tourist destination.
However, its isolation is compensated by the other airports that surround it, such as Fiumicino and Ciampino, less than 30 minutes away by train. It also has rail links with Pisa, Naples and Florence.