My apartment is literally at the NDK major station of Sofia's subway ("Metro"). It takes a minute to get on a train to the airport or any other part of town. There is also a taxi stand in 100 meters from the building - an even easier 24-hour option to get around for about 2 euros one way.
You can rent a bike 900 meters from my apartment from Sofia Bike Rental, located at 19 Shesti Septemvri Street for 9 euros per day. There are free guided bike tours of the city by an NGO Sofia Green Tour in English. Vitosha street is Sofia's version of the Champs-Élysées. All the cafes, restaurants, luxury shops, theaters, art galleries and government headquarters are within walking distance. This is your neighborhood if you are a city person, enjoy shopping, socializing and people.
If you like history and ancient architectural remains you can walk to the nearby remains of a Roman amphitheater in the Ancient Roman city of Ulpia Serdica.
The apartment is located across the street from NDK park where you can walk through beautifully arranged gardens and enjoy a vast display of water falls and fountains - a delightful show both day and night.
Theater, opera and balet aficionados will be happy to discover tens of options in my neighborhood - Ivan Vazov National theater, Sofia Opera and Balet, Bulgarian Army Theater and many more...
There are temples, churches and mosques in the immediate vicinity - Alexander Nevsky Cathedral, Sv. Nedelya Orthodox Church, The Synagogue of Sofia, Banya Bashi Mosque in Sofia and many others, some dating back to Roman times.
If you like art you'd love to visit the National History Museum, the National Gallery for Foreign Art with artifacts from as far away as India's Goa province, the National Art Gallery, the Earth and Man National Museum (one of the biggest mineralogical museums in the world) and many other galleries and museums. The Museum of Sofia history is located in the building of the Sofia Old Mineral Baths in the center of the city.
Sofia has its own zoo, a circus, IMAX movie theaters, shopping malls, karting race tracks, Vitosha mountain skiing and snowboarding and many more entertainment opportunities. My apartment is unique in that it is located in the very heart of Sofia - Vitosha and Patriarch Evtimii streets. Yet the views of Vitosha mountain out of the windows are breathtaking - you will feel like in a 5-star Alpine resort.
Off-street parking is available within 400 m - an underground heated public parking garage with 24 hour onsite security.
Late check ins after 10 PM (22:00) are welcome - I will accommodate in whatever way I can.
The local currency in Bulgaria is called LEV (LEVA in plural). Its international currency code is BGN. Its exhange rate is fixed at 1.96 BGN for 1 EUR, i.e. there is a currency board in Bulgaria.
Here is the Bulgarian LEV approximate rate against other currencies (subject to daily changes, not updated regularly here):
₤1 = 2.26 BGN (2 LEVA and 26 STOTINKI)
€1 = 1.96 BGN
$1 = 1.85 BGN
100 Russian rubles = 3 LEVA and 19 ST.