Bulgaria: Rila traverse, Rila Monastery and Seven lakes - 6 day hut to hut (хижа or Chalet)

World class hut-to-hut multi-day trek across Bulgaria's Rila range. All nights are spent in mountain huts (Chalet or хижа) without any camping. Mid June to mid September is generally good season weather-wise and with all lifts working (some are off outside the "summer"), but difficult weather can turn dangerous at any time of the year, so come prepared! The sunniest weather is generally from mid August to mid September.

The conditions in the huts are fairly basic overall, with some big variety between them. Most provide linen but bringing your own liner is recommended. Food is always provided but choice can be very limited. Toilets are usually outside and not the cleanest (some exceptions), and hot water or showers are never available except washing up in icy streams.
Booking ahead the huts is not necessary except summer weekends. It's not too difficult, despite the language barrier, by using Viber, the most common messaging app in Bulgaria. Simply message the mobile phone numbers provided below via Viber, and not SMS, Whatsapp, email or other methods. Calling is also OK, but it's actually easier to communicate by text when the other party's English level is unknown.

Day 1 - Get to the Yastrebets cable car station in Borovets (70km from Sofia); Ascend ~1000m by cable car (8:30-17:30 daily except Mon and Tue) to 2000m at Yastrebets Hut and have lunch with the view; Walk 5km and 700m up via Musala Chalet (2400m +359 89 6661454), to Everest Chalet (also called Ledeno Ezero shelter, 2700m, dorm without shower or water, outside toilets +359 88 8590342).
Day 2 - Walk 9km, 300m up to 2900m Musala peak then 700m down to Granchar Chalet (2200m, dorm/room, no showers, outside toilets +359 88 4261159).
Day 3 - Walk 15km, 400m up then 400m down to Ribni Ezera Chalet (2200m, dorm/room, inside toilets with cold water +359 89 9103275).
Day 4 - Walk 18km, 1050m down to Rila Monastery - the second half is on tarmac and can be hitched usually (1150m, several options to stay, including the Rilets Resort & Spa hotel).
Optional: Around the monastery is a great location for a day off to rest from the trek.
Day 5 - Walk 14km, 1300m up to Ivan Vazov Chalet (2300m, dorm with inside toilet and cold water - this was the best hut with visited, with the best food and attitude +359 88 7727772). Note: If you don't fancy a 1300m climb then you can take transport from Rila monastery to the bottom station of the Rilski Ezera cable car, and take it up to the 7 Rila Lakes area. This way you'll face just 500m climb to arrive at Ivan Vazov hut from the opposite direction. There're a couple of circular day walks from this hut - recommended!
Day 6 - Walk 10km, 300m up then 500m down to the popular 7 Rila Lakes area, popular with day visitors arriving by Rilski Ezera cable car (9:30-16:00 off on the last Monday of the month). You can use the simpler Seven Lakes Chalet located among the lakes (+359 88 2506060) or the hotel-like Rila Lakes Hut just at the top cable car station (2100m, with private rooms and hot shower).
Day 7 - Descent ~1000m by the "Rilski Ezera" cable car to the lower station. 86km to Sofia or Sofia airport. Optional: Stop at Sapareva Banya for the Kotvata hot springs complex - the outdoor pools are the main attraction and well worth your time: https://aquaclubkotvata.com/outdoor-pools/

Borovets "Lift Yastrebets" gondola (Wed-Sun 8:30-17:30 - Monday and Tuesday off!): https://www.borovets-bg.com/en/page/info/lifts-trails/lifts

Rila Lakes hut and cable car (9:00-16:30 daily): http://www.rilskiezera.bg/?act=content&rec=51

Local site in English: https://bulguides.com/self-guided-rila-traverse/
Huts map: https://www.google.com/maps/d/viewer?mid=1svVHTWCYueieBOhj6FM5kD-eNww

Alternative days 4-5 (not recommended): It is possible to walk from Ribni Ezera Hut to Ivan Vazov Hut via the alpine zone, without descending to Rila Monastery. The night is spent at Malyovitsa hut (1900m, dorm/room + hot shower), but this option has major drawbacks: skipping the monastery (one of Bulgaria's main tourist attractions) and increasing ascent/descent by extra 300/400m, while the route is about the same length.