Booking.com is a service for searching and booking hotels, apartments, hostels, boarding houses, and holiday homes. Very comfortable. All you need to do is enter dates, the number of guests, and the destination. The service provides a wide range of filters; based on your requests, and you can narrow the search by the necessary parameters.
Greenkey.global is the site of the international Green Key certification program organized by the Foundation for Environmental Education (FEE). Here you will find all hotels, hostels, campings, restaurants, beaches, and even parks that have received the coveted green sticker, which means they have passed the certification for the environmental friendliness of the tourism business.
Skyscanner. Flight search service and more. Here you can buy plane tickets at the best prices. You can choose according to individual parameters or give preference to an eco-friendly air carrier. If it turns out that an electronic boarding pass is available on your flight, then it will be activated directly from the application; you will not need to print a paper copy.