Mount Vitosha to the south is just a 20 minute drive from Sofia. Our hotel booked us a taxi to Simeonovo so it was a quick, safe and cheap journey. You can get the 122 bus also which would be the cheaper and slower way to Simeonovo.
We then got a cable car to Aleko high up the mountain which was great fun. The Cable car may only be open weekends and bank holidays out of season, we went on the Bulgarian Orthodox Easter Day which is a national holiday. The cable journey itself took around half an hour and rises over 1km above sea level. The views are superb.
In Sofia the temperature had been hitting around 25 Degrees Celcius. The temperature on the mountain was actually pleasant but my feet were frozen as all I had to wear were Converse trainers. There was still plenty of snow on the mountain, the pistes were open and people were skiing, snowboarding and sledging.
You could easily spend the whole day roaming the mountain, but given the snow and our attire, we were not really equipped for that. We spent a pleasant hour or two watching the skiiers and marvelling at the views. There is a cafe on the mountain but it did not look that inviting.
We grabbed a taxi back to the city and forgot our own advice and did not check the rates in advance, so it was a pricey return.