Last night I met some friends for dinner and drinks at Changi Village. It’s a great little spot, and it feels a world away from the city. (By public transport, it sort of is). The buildings are a little lower here, the trees a whole lot bigger. I heard more Hokkien than Mandarin or English.

As I walked through the hawker centre and to the pub, I passed a bunch of tables being set up for a festive dinner. It’s the seventh month of the Chinese lunar calendar, widely known as the Hungry Ghost Festival, and these community dinners aren’t an unusual sight in Singapore. It is a time when the lines between this world and the next are said to thin, and paper offerings are burnt for unseen visitors from far away. As I walked down the hill and towards the beach, my path was littered with bits of joss paper and hell money; the smell of smoke from big metal urns mixed with the brackish smell of the strait.

The beach was crowded too, with people of all ages playing Pokémon Go. A young couple sat under a tree, their faces glowing in the shared light of a single phone. A man in his sixties plodded gently behind his grandson, laughing as he exhorted the kid to slow down.

Later at the pub, it struck me that most of these people — both the people celebrating Hungry Ghost Festival and those playing Pokémon Go — were prompted to occupy and activate a physical space because of things unseen. Two invisible realms, the virtual and the spiritual, had superimposed their cartography on the physical world.

Now obviously there are great differences between a religious festival and a video game, and I am certainly not trivialising spiritual practices. What interests me is the ways in which our use of space can be reshaped by things not visible to the naked eye. Only a spirit medium or a smartphone could decipher the invisible forces that brought some of those people to Changi Village last night. And in both instances, real-world currency had been spent on items for unseen worlds: the worshippers had bought paper offerings for visiting ghosts; the gamers had bought in-game items to attract virtual monsters.

Last night I was reminded how we often can’t see the things that shape urban processes, that we are blind to the invisible lines that are drawn over the physical landscape. We live in a world criss-crossed by lost roads and half-grown paths trodden by people over the course of centuries. Our vistas are shaped by sight-lines drawn up by planners and by accidents of history. And often, sites of great community or spiritual significance endure — even as the cities and cultures around them change.

As augmented reality technologies become more widespread, what sites of virtual significance are going to be drawn over the invisible lines already shaping our landscape? What digital ley-lines and holloways will sit beside ancient roads and pilgrimage routes in these virtual maps of the world?