Jomifl – To answer your question. Yes it is “preferred” in Islam ton do your prayer in congregation (together) as it is considered 27 times better than prayers offered on your own. Usually in Muslim countries you have masjids (mosques) almost at walking distance from wherever you live so people do go there five times a day. However if you do not live near a masjid then you may do your 5 time prayer at home. But still (2 or more) people at home or anywhere (without causing a problem for others) can offer prayer and that would be considered as congregational.
I go to play cricket on weekends and I usually offer my afternoon prayer where ever we are playing match. I usually find a quiet corner where I would not offend anyone, and whole prayer takes only about 3 to 4 minutes. Having said that Islamic prayer has not got anything that should offend anyone. Because for occasional prayer there is no special requirement whatsoever. Apart from enough space for a person to sit, clean space without any clear filth and that’s all. But if few people feel that they have to be offended then there might be a different reason.