I decided to write this tips as a warning or danger as Yerevan is a traditional ex-Soviet country. That means that Comrades were expected to go to the toilet at home, report for work (and use those facilities) and go home again. Restaurants and bars are mostly recent creations. Public toilets? No way. That would be an excuse to be on the streets and talk secretly. Also that would be a public convenience in a Soviet world where no one thought of that. So I never found one!
I did find an excellent solution for you!
Please read on.
The Marriott Hotel - right in Republic Square - has excellent toilets! They are actually through the lobby and up the stairs. They are massive, clean, modern and you will have them all to yourselves. As long as you look reasonable you can go straight through and use them. You can also pop into other luxury hotels, but there are not many of them. Yerevan is not an easy place to do your natural business.
The pictures are of the Men's toilets (only). If you have never seen a urinal or are easily offended - please do not look past picture 2.
I booked car rental online through Hertz. A Niva 4x4, incidentally, is ideal: they are robust and built for the type of roads you will find in Armenia. Because my previous rental with Hertz had been completely messed up, I had a substantial voucher towards the cost of the rental. The local office refused to accept it. In case there is any doubt: this is a Hertz office refusing to accept a Hertz voucher which clearly says it is valid worldwide. So I paid with a credit car and told them I would take it up with the company. Apart from the vehicle having a defective petrol gauge (and a few other minor problems), there were no further difficulties until I returned it, quite clean, and was charged a cleaning fee.
Hertz Customer Relations refunded the cost of the voucher and the cleaning fee - Hertz agree that unless the vehicle is excessively dirty, there is no such fee - and expressed concern at the state of the vehicle provided to me. However, Hertz say "Please do note however that we can only act when the rental has been closed, during the rental the location should be your first point of contact." So it seems that you query any problem - query every potential problem - with the local office and pay up for whatever they insist upon. Then, afterwards, you can refer it to Customer Relations. I leave you to draw your own conclusions about car rental in Yerevan.
Hiring a car in Yerevan is not usually recommended. Personally, I didn't think driving was too difficult but there are some potential problems and if you're at all nervous about the idea, don't do it. There are coach trips you can book at reasonable prices but the convenience of having a car for Geghard and Garni or Sevan, for instance, makes car rental an interesting option.
Traffic in certain parts of Yerevan can be congested although the one-way system in the centre of the city does make that part relatively easy. These are some of the difficulties when you start travelling around:
(i) The road surface can be very poor. The main road from Yerevan to Sevan (and along the side of the lake) is fine. Turn off that road and you are likely to find yourself weaving to avoid - if you can - very big potholes. In a nutshell: it's unpredictable.
(ii) The signposting can be a major problem. This is not because it is in Armenian script, it is almost invariably in Latin script as well, (although you might memorize what Yerevan looks like in Armenian, i.e. something like 'trtqul'). The real difficulty is that, although the signs on major roads are good, if you're not approaching somewhere from the obvious direction - maybe you're driving across Yerevan to get out the other end - there may be no signs at all. Everywhere, not just in Armenia, there are plenty of other drivers who assume you know where you're going. You need time to think; you don't have it. It is also worth mentioning that getting a good road map of Armenia is not particularly easy in Yerevan.
(iii) There are not many missing drain covers in the middle of the road but there are some. Let's face it, you only need one....
(iv) As pointed out by others on VT, being a pedestrian can be hazardous or, from a driver's point of view, pedestrians can be a hazard! The standard technique for crossing main roads is to take minimal notice of traffic lights, pedestrian crossings and so on, walk into the middle of the road, stand there willing the drivers not to hit you and, when there's a space, complete the crossing. It happens elsewhere too but the Yerevan method is particularly disconcerting for a visiting driver or pedestrian until you (hopefully) get used to it!
There are probably only two banks that change travellers cheques and they know it. One of them is HSBC. It charges flat rate of equivelent of 17USD for a transaction. So the more you change the better - ha, ha, ha, this is what the bank thinks too!
............. and traffic lights are a waste of bulbs!!! Be very very careful when crossing the streets especially in the city centre. No matter if the lights are green, you must be extremely careful. Car drivers tend to speed up on crossing people, and you'll never know from which way the cars should be coming.
Yerevan is as save or unsafe as any other city on the planet. You must be aware of you surrounings in any city. I felt totally safe here, I couldnt have stood out more here if i would have been wearing a Polka dotted suit, and at times i did draw attention to myself. Never the less the people of Armenia were great. Just do as you normally would being a stranger in a new city. All the rules apply!