For several years, I spent most of my working days drawing boundaries. I’d follow along watersheds in a digital elevation model (DEM) or a visible ridge in a properly georectified image. Others, I’d trace along the middle of a river, wondering what it was like for the people living on the shore. And on some lucky days, I could connect demarcation pillars or monuments visible in satellite imagery (that was the best because it meant I knew exactly where the boundary was supposed to go). In all my imaginary travels along international boundaries through large-scale imagery, I would let my mind wander, thinking about what it would be like to actually visit or live in this city split between two States, or on this beach with waves lapping at a land boundary terminus pillar.

I love to travel, and I want to go everywhere. There are very few land boundaries that I’ve worked on where I thought, “No I wouldn’t want to visit this place.” And even for those, I could pick out more than a few positives if presented with an opportunity to see them. It was easy to choose my top boundary to visit but much harder to select another two from my never-ending list of places I’d like to see. I have a whole tab on my personal travel wish list labeled “boundary tourism.”

No. 1: Mt. Roraima, the Brazil–Guyana–Venezuela Tripoint

This was my first entry, way back in 2014, when Sovereign Limits was a yet-unnamed project I was working on in my spare time. Mt. Roraima towers 400 m (1,300 ft) over the surrounding plains in the Guiana Highlands, and, as a distinctive geographical feature, it has been used since the 19^th century by colonial surveyors as a reference point for the various abutting boundaries and probably by indigenous peoples before. While it was monumented, likely sometime in the 1930s, there was never an official trilateral Agreement between Brazil, Guyana, and Venezuela, or their colonial administrators, because Venezuela has intermittently disputed the location of the tripoint. It is currently in conflict, and Guyana has brought a case before the ICJ over their entire land and maritime frontiers with Venezuela (Venezuela claims about half of Guyana, up to the Essequibo River).

The tripoint is located on the plateau, somewhere along the watershed at its peak. It is very difficult to precisely determine the location of this tripoint since coordinates are not available in a modern datum and the plateau has received some very interesting and sometimes conflicting georectifications depending on the image source, leaving potential locations for the tripoint as much as 250 m (820 ft) away from each other.

But there are guided, pack in, pack out hiking/camping trips to Mt. Roraima, all of which feature pictures with the tripoint as an adventure highlight. There are also epic waterfalls and views, but really, it’s all about the tripoint, right? It’s supposed to be one of the best hikes in Venezuela. How could you not want to visit such a breathtaking mountain? And how could I resist the temptation to scramble up with a Trimble or some other precise GPS unit and take my own coordinates in WGS-84 and get that tripoint on the map exactly where it belongs, dispute or no dispute?

No. 2 Belgium–Netherlands Land Boundary

Belgium has some very neat boundaries. In addition to the funkiness with the Netherlands discussed in greater detail below, Belgium also has some weird German enclaves created by an old rail line, the Vennbahn, that has since been converted to a bike trail that I will someday ride through.

But even more, I want to visit Baarle-Hertog, a Belgian enclave in the Netherlands’ town of Baarle-Nassau. Baarle-Hertog is a series of enclaves nested within one another like a donut hole in a donut on a plate or, perhaps more fitting, a wheel of Dutch gouda, filled with Belgian passendale, with its holes filled with Dutch edam. Cheese-ception? Maybe.

Just regular enclaves, small territories of one country fully nested within another, are weird boundary scenarios, but the international boundary between Belgium and the Netherlands is next level. Belgian Baarle-Hertog consists of 24 separate parcels, 21 of which are fully enclaved by the Netherlands. Within the two largest chunks of Baarle-Hertog are seven separate Dutch enclaves, not to mention the additional Dutch field just across the primary international boundary in Belgium. The boundary weirdness stems from medieval land exchanges but was finalized in 1995. The border is fully demarcated, even as it splits buildings and gardens. One NPR article notes that in the course of a minute of quick walking, it’s possible to cross the international boundary five times. I cannot wait to do this.

No. 3 Gibraltar

Gibraltar is a place I’ve wanted to visit long before I was researching boundaries. There were epic pictures of the Rock in various middle and high school history textbooks. What a site, situated on the edge of the Mediterranean Sea and Atlantic Ocean, mirrored by another limestone pillar on the African continent at Jebel Musa in Morocco. As I began to learn more about the short, only 1.26 km (0.78 miles) disputed boundary, it edged towards the top of my must-see list.

In addition to its epic beauty, Gibraltar has a lot of strategic value, and the United Kingdom (just Great Britain at the time) gained control of it way back in the early 1700s during the War of Spanish Succession. There is a 1713 Agreement in which the Spanish king renounces all claims to Gibraltar and its fortifications to Her Britannic Majesty. Since then, there have been sieges and battles and world wars, but the UK has retained control over Gibraltar despite Spain’s continued protests.

I would like to explore Gibraltar for its beauty, the Moorish–Spanish–British history, the maze of tunnels running through the Rock, and most of all, its little boundary, which is almost entirely an airport on the British side.

The exploration of international boundaries in satellite imagery and dreaming about traveling to them has been a fun aspect of my job and has provided entertainment during the monotony of tracing a riverine or watershed line. I cannot wait for my first trip to an international boundary armed with the knowledge of its history and construction.