I always fantasized working for a particular company because of their leadership in the market and the projects they implement as it relates my area of knowledge. However, this company hasn't advertised or even done any job postings recently. So my gut tells me to go their HR office and show them my resume in the hope that they will call me when a need arises.
I don't know if there is a need now, but is it possible or a good move to visit their HR office? I honestly need advice here.
HR is the wrong place to send anything unsolicited. In order to get hired, you need to talk to an actual "hiring manager". So, the first thing is to get contact information of such people and you want to talk to multiple people. Once you have their information, sending a resume is the wrong first move. You want to be asking questions about what they are doing, what problems they are facing and solving, and what skills they are looking for at this time. The point is to be "networking" with them first, not asking them for a job. You might find that you need to learn new skills before you would be a good candidate for them.
There is no need of visiting its HR office and it's not a good move
Probably your best approach to what you want, is sending to the company an email explaining your interest on working there, i would evade sending your CV in this first contact, you should ask first and see if they're interested too.