Approach from Poland:
Bulgaria has a quite good transport links with Poland. The easiest way to reach the Rila Mountains is to start in Sofia. So we have a few options:
- aircraft - Polish airlines LOT offers flights from Warsaw to Sofia, in 2010 when booking ticket about 3 months in advance, the price of round-trip is approximately 300 zł (75 Eur),
- bus - is a lot of lines offering connections from various places in Poland to Sofia, the price of round-trip is about 400 zł (100 Eur),
- car - the route through Slovakia, Hungary, Serbia - personally checked, as I've heard this is the fastest way, but You have to take into account the possible queue at the Serbian - Hungarian boarder (external boarder of the European Union - we stood 7 hours) and paid motorways,
- the train - also personally checked, the way is through Slovakia, Hungary and Serbia. I advise You against buying a ticket in Poland because of the crazy price (about 1000 zł in one direction, sic! means 250 Eur). But in neighboring countries, including Slovakia, you can buy such a wonderful "invention", as so called City Star ticket. The essence of this ticket is that the first person pays 100% of the price and each of the next half price (max. 5 people per ticket). We, means - 2 people, paid 153 Eur for round-trip, from Slovak city Zilina to the Serbian-Bulgarian border. So about 300 zł (75 Eur) per person for round-trip. I think that it is quite cheap. Of course, you need to add journey to Slovakia, we crossed the board by walk :) in Zwardoń (Poland) and in Skalite (Slovakia) bought a ticket to Zilina for approximately 2€ per person. There is one more question left - how to cross the Serbian - Bulgarian boarder. Unfortunately, City Star tickets can be purchased only on specific routes - but don't worry, You can make an additional payment in the train. I did so, and the conductor took from us only 5 Eur. What is more, when we were leaving he said to us: "Poland is not dead yet" (these are words from Polish national anthem :) ). Transfers in the following cities: Bratislava, Budapest Train Kaleti, Belgrade. For more information on ticket City Star on Slovak railways: http://www.slovakrail.sk (Unfortunately only in Slovak).
From Sofia you can get to various villages / towns near the Rila mountains. We stood on first night in Samokov (less than an hour drive from Sofia). Samokov is relatively big town, and from here to the mountain resort Boroviec is only about 10 km. Important notice: from Sofia to Samokov (and Borovec) buses depart from South Bus Station (only!). To get there from the railway station the easiest way is to use the subway.
Reservations can be made by mail. Prices are reasonable (there is a lot of promotions), rooms have shower and toilet, to the center of Samokov is approximately 15 minutes by walk.