The world's smallest countries, and my life's goal

I've always been fascinated by microstates and city-states - sovereign nations that in some cases are only a few square miles in size.

I find them interesting for a variety of reasons. These little nations - many of which are smaller than inside-the-loop Houston, some which which contain only a few thousand residents - somehow manage to exist among the likes of China, India, the United States, Brazil, Russia.

Their histories, in many cases, are fascinating. A lot of European miscrostates, for example, are vestiges of feudalism. The co-princes of Andorra are the President of France and the Bishop of Urgell: an arrangement dating back to 1278. Liechtenstein is considered to be the only surviving remnant of the Holy Roman Empire. The Marshall Islands, Palau and the Federated States of Micronesia, on the other hand, are groups of Pacific islands the United States acquired after World War II which, although now independent, still rely on the United States to provide basic services such as postal delivery.

A lot of these small countries face significant hardships. I've already written about the heart-rending tragedy of Nauru, for example. Nauru's low-lying island brethren - Tuvalu, Kiribati, the Maldives - face grave threats from rising sea levels.

These are the 25 smallest countries in the world, by total area. The overwhelming majority of them are island nations:

1. Vatican City (0.17 sq mi) - Europe (completely surrounded by Rome, Italy)
2. Monaco (0.78 sq mi) - Europe (located along French Mediterranean coast)
3. Nauru (8.1 sq mi) - Pacific Ocean (single island)
4. Tuvalu (10.0 sq mi) - Pacific Ocean (multiple islands/atolls)
5. San Marino (23.6 sq mi) - Europe (completely surrounded by Italy)
6. Liechtenstein (61.8 sq mi) -  Europe (located between Switzerland and Austria in the Alps) VISITED 7/2016
7. Marshall Islands (69.9 sq mi) - Pacific Ocean (multiple islands/atolls)
8. St. Kitts and Nevis (100.8 sq mi) - Eastern Caribbean (two islands) VISITED 6/2015
9. Maldives (115.1 sq mi) - Indian Ocean (multiple islands/atolls)
10. Malta (122.0 sq mi) - Mediterranean (archipelago located due south of Sicily, Italy)
11. Grenada (132.8 sq mi) - Eastern Caribbean (archipelago)
12. St. Vincent and the Grenadines (150.2 sq mi) - Eastern Caribbean (multiple islands)
13. Barbados (169.5 sq mi) - Eastern Caribbean (single island) VISITED 6/2015
14. Antigua and Barbuda (169.9 sq mi) - Eastern Caribbean (two islands) VISITED 6/2015
15. Seychelles (174.5 sq mi) - Indian Ocean (archipelago off the east coast of Africa)
16. Palau (177.2 sq mi) - Pacific Ocean (multiple islands and atolls)
17. Andorra (180.7 sq mi) - Europe (located between France and Spain in the Pyrenees)
18. St. Lucia (237.8 sq mi) - Eastern Caribbean (single island) VISITED 6/2015
19. Federated States of Micronesia (271.0 sq mi) - Pacific Ocean (multiple islands and atolls)
20. Singapore (276.4 sq mi) - Asia (archipelago located at southern tip of Malay Peninsula)
21. Tonga (288.4 sq mi) - Pacific Ocean (multiple islands and atolls)
22. Dominica (290.0 sq mi) - Eastern Caribbean (archipelago)
23. Bahrain (295.4 sq mi) - Asia (archipelago off the northern coast of the Arabian Peninsula)
24. Kiribati (313.1 sq mi) - Pacific Ocean (multiple islands/atolls)
25. São Tomé and Príncipe (372.2 sq mi) - Africa (archipelago off the western coast of Africa)

The "top 25" is a good cutoff, because the next smallest country - Comoros - is almost twice as large as São Tomé's 372 square miles. For purposes of comparison, Harris County is 1,777 square miles in area. Inside-the-loop Houston, i.e. the area of the city encompassed by 610, accounts for approximately 96 square miles of land area.

The world's smallest countries also tend to be the world's least populous (for good reason; there's only so much land available for people to live upon). Of the 25 smallest countries by area listed above, only four - Bahrain, Singapore, Malta and the Maldives - are not also among the 25 smallest countries by population. Malta and the Maldives, in fact, fall right outside the smallest 25; Singapore, on the other hand, has a population of almost 5.5 million people, making it more populous than Norway, Ireland or New Zealand.

Anyway, my focus is on the smallest countries by area, not population, and I want to visit all 25 of the countries listed above before I die.

Yes, it's a rather esoteric goal. But it's really no different than those who endeavor to visit all 30 Major League baseball parks or all the National Parks of the United States within their lifetimes. And no, it's not my life's only goal; it's just something I'd like to accomplish.

Some of these tiny nations will be relatively easy for me to visit. Vatican City, home of St. Peter's Basilica and the Sistine Chapel, is a mandatory part of any tour of Rome. Monaco should be easy to visit if I ever tour the French Riviera. Andorra is a bus ride from Barcelona. Other places will be a bit more difficult to visit. Trips to The Maldives, Seychelles and Bahrain would probably require me to transfer through Dubai. In order to get to The Federated States of Micronesia, Palau or the Marshall Islands, I'd need to use United's "Island Hopper" service that operates between Guam and Honolulu. Getting to São Tomé and Príncipe, would require first flying to Portugal, Ghana or Angola. And in order to get to Nauru, I'd need to first fly to Fiji (which, believe or not, is not even in the smallest 40 countries) or Australia, and then take a plane to the imperiled phosphate island. Visiting some of these countries also requires applying for visas, and a couple of them might not be particularly safe to visit right now.

My quest to visit these countries began in earnest last month, when I visited St. Kitts (the smallest sovereign nation in the Western Hemisphere), Antigua and Barbuda, St. Lucia, and Barbados during a cruise of the eastern Caribbean. I was only at each of these places for a few hours apiece, while my ship was in port, but I went on tours of each of these countries, stood on their soil, took in their sights, met their people and ate their food, so I can say I've been there.

That's 4 out of 25 microstates, or 16%. It's a start. Can I get to the other 21 before I shove off this mortal coil? I'm going to try.

UPDATE (August 2016): I spent the night in Liechtenstein during my (all too short) trip to Europe last month. That gets me to 5 out of 25, or 20%.