For short-term relationships and sex, you may want to look for someone during your night life—particularly at bars, clubs, and restaurants. Individuals at such venues may be more likely to have similar short-term and sexual goals as well. Also, bars and clubs may offer a better chance of getting noticed, flirting, and touching to build sexual attraction. Such meetings may still require self-introduction though. Therefore, you may have to overcome anxiety, learn to break the ice, and ask for what you want to begin an interaction. In this case, however, a bold pick-up attempt and being direct with your interest may help increase your chances of finding a like-minded lover.
Your question may be answered right there and then. Normally this doesn't happen on your first try though so don't get discouraged. Wouldn't it be great if you didn't even have to ask where to meet older women, because that older woman may be wondering where to meet you! (In fact, while I was looking around online I found a lot more sites where the women are actually looking for younger men.)
When you approach in a confident, easy-going way, most women drop their guard and open up to the conversation. However, if you approach in a nervous or appear intimidated by the women, they will automatically close off to you and the conversation. Why? Women are attracted to the strength in men and turned off by the weakness. This is why confidence is the #1 thing you need to have before you begin trying to meet new women.