Easily the best travel investment I’ve ever made are reusable water bottles. In Europe, I’ve been trying a Water-to-Go bottle. These bottles are fabulous and have in-built water filters so you can drink water from taps all over the world without worrying about getting sick. You can even drink from streams and rivers too! I take a bottle everywhere with me, and they have saved me hundreds of pounds on bottled water and saved me from buying hundreds of plastic bottles. Do you have a bottle like this? If not, then go and get one, they are life-changing!