There are people who collect just about anything that you can imagine. Although many people think automatically of collectible stamps or rare dolls, the hobby of collecting can get into some niches that you might never have considered. Antique bottle collecting is one such area. There is a very devoted group of collectors in the world who are carry with them an almost encyclopedic knowledge of glass making history. These people can tell you not only what bottles are hard to find, but also what color of glass can make one bottle many times more valuable than an exact replica in a more common hue.
Bottle collecting is a hobby that often starts when collectors are young. I personally spent many days playing in the woods near my house when I was a youngster. My friends and I would find many old bottles almost any time we ventured out to play. I never quite understood where all of the old glass treasures came from, but we found plenty just in our normal day to day adventures. Unfortunately, at that time, we usually ended up using what we found for slingshot target practice, but I did save a few that caught my eye, even back then. What usually made me notice a particular bottle was unusual colors or shapes. My instinct was good I suppose. It turns out that antique colored bottles can be very valuable.
Serious bottle collectors go on much more formal expeditions in search of the glass artifacts. Favorite sites to check include the areas around streams and rivers. Old bottles that were thrown away by careless people often find their way to the shore. These can sometimes be found without having to go to the trouble of too much difficult digging. Of course, if you are going to try this yourself, it is wise to be very careful as these spots can be rather treacherous. Taking along a digging buddy would probably be prudent.
Once you have found a few old bottles, doing research on them can be quite entertaining. Whether you find a rare beer bottle from a long closed brewery, or an antique milk bottle from a local dairy farm that no longer exists, there is a wonderful connection to the past that anyone can enjoy.