This become more or less just a list of places and things. Usually these are the places what I recommend to colleges and friends visiting Budapest.
Eating and drinking
Caffees
There are quite a lot of good caffe places in the city. Check for a collection in https://europeancoffeetrip.com/budapest/
Espresso Embassy
https://europeancoffeetrip.com/cafe/espressoembassy-budapest/
https://maps.app.goo.gl/QwbfS6hLBArWR1mf9
One of the classic speciality caffe bars in 10 min walking distance from the conference location.
Zërgë Coffeeshop
https://europeancoffeetrip.com/cafe/zerge-budapest/
https://www.facebook.com/zerge.bp/
https://maps.app.goo.gl/L7cqj1YtbXmjpGgh8
An other good caffe bas on the Buda side, still no more than 15 mins distance from the InterContinental.
Mantra Specialty Coffee Bar
https://europeancoffeetrip.com/cafe/mantracoffee-budapest/
https://maps.app.goo.gl/2EK5dJTwS8SMk41m6
Another classic speciality coffee bar in downtown.
Nor/ma Grand
https://europeancoffeetrip.com/cafe/normagrand-budapest/
https://maps.app.goo.gl/E8p9JSr1qfFxikyH6
Speciality caffe and bakery on the Buda side.
Streetfood
hummusbar - hummus bar
https://maps.app.goo.gl/kJdL34hoSDCDgwAt5
The name tells it all. It is a franchise with lots of locations in Budapest. Each of them have some small differences. This one in the Október 6 street has laffa baked in a traditional oven.
Trattoria Pomo D'Oro
https://maps.app.goo.gl/qxh4onVmRZG387mr8
A bit upscale pizza restaurant in downtown Budapest. I've never been here, I like Pizzica more and it is only 15 min walking distance form Pomo D'Oro.
Sao - asian
https://www.facebook.com/saofoodandbar/
https://maps.app.goo.gl/mbwkEbjW2kRJi5379
Chinese, thai and viatnemese cousin in the middle of the city. The restaurant is in the middle of Gózsdu udvar what is a several blocks big are covered with caffes and different restaurants.
Dobrumba
https://maps.app.goo.gl/s5Ui7uuDUtiWQMQc6
From the Atlas to the Arrarat, oriental and middle asian food. The place is in the former Jewish getto of Budapest what is not considered as the heart of the city. (Some youngsters also call it as the party district or the bermuda triangle)
Dobrumba has a brother restaurant Pingrumba in the Buda side. It is recommended to reserve table in both of the restaurants.
Biang- chinese
https://maps.app.goo.gl/3zn6MguKBkbXV8hp7
Best chinese noodle place and it is very close to the market hall what is also nice to see. You can get to it from the conference place with the tram number 2.
Pizzica - pizza restaurant
https://www.facebook.com/pizzicapizza/
https://maps.app.goo.gl/xAUfPLaRfT7685sHA
This is the best pizza in the Pest side and probably in the whole city. It is an underground hipster Napolean style pizza slice bar operated by 2 Italian brothers. At the same time it is also a gallery.
IGEN - pizza restaurant
https://www.facebook.com/igenitalia
https://maps.app.goo.gl/qVrH1gjbJyDXpNM67
This is maybe the best pizza place in the Buda side. It is more upscale than Pizzica and have more sitting places, but it has less authentic vibe. The name igen, means yes.
Upscale restaurants
MAK
https://maps.app.goo.gl/kmFY7EPmcua9u3FV7
Fine dining restaurant with tasting menu. The usual fine dining things, using local materials from Hungary or neighbouring countries, all organic and so on. I've been here only once a loong time ago.
Costes downtown
https://costesdowntown.hu/etelek-es-italok/
https://maps.app.goo.gl/M4qdaQxWETs69y5n8
Fine dining restaurant with tasting menu. Its brother restaurant was the first restaurant in Budapest to receive a Michelin star. I've never been here, it is just too expensive 
The owner of the restaurant is the same person who started and co-owned the Sziget festival.
Bakeries
If you like pastries you need to try "Kakaős csiga" cocoa spirale and "Túrós batyu" cottage cheese filled thing.
Butter Brothers Bakery & Bistro
https://www.butter-brothers.com/
https://maps.app.goo.gl/nXtFUAaVHS74bkm79
Best kakaós csiga in Budapest.
Bars
Kisüzem
https://www.facebook.com/Kisuzem
https://maps.app.goo.gl/ZtmPqTYXcQMAxh5r6
A typical bar in the middle of the former ghetto with underground and hipster crowd. It has some good food also and sometimes it operates as a galery.
Toldi
https://maps.app.goo.gl/p4UZhXvrnZWmXXuJ6
Bar and party place in the lobby of a cinema,
Szimpla
https://maps.app.goo.gl/WeGT9Pu52GUH2N266
The mother of all ruin bars in Budapest. During the early 2000's a set of new places opened in the unused building of the inner city and they lighted the vibrant nightlife of the district. This was the first bar like that and it is still a classic. There are lots of tourists here as this place is also advertised heavily in tourist magazines.
The other most famous Hungarian musician is even less known.
Seeing
Places, buildings
Parliament
https://maps.app.goo.gl/5dpA8uXDFhWbLYYF6
It is nice to see it from close and from far. If you would like to make this kind of a picture you need to go to the other side of Danube, to Batthyány square
St. Stephen's Basilica
.https://maps.app.goo.gl/uzfqMy8wKvBxyMPr7
I would recommend to take the time and walk to the top of it. The view is nice there.
Castle district
https://maps.app.goo.gl/PEL6g7ft4DKdkaUr7
There are lots of things here, like the Matthias Church (that stripped roof in the picture), the Fisherman's Bastion (from where this picture was made) and the actual castle.
From the conference place the best way to get there is to cross the Danube on the Széchenyi Chain Bridge and either walk up in the stairs or take the funicular.
Yes, Budapest has a funicular also.
Citadel lookout
https://maps.app.goo.gl/GmewcBWVNhyvBpWh7
This is the place to make this panorama of the city. Pro tipp: you can walk up from the Buda side of the Erzsébet Bridge.
(Now Google maps tells me that the place is temporarly closed, what is difficult to interpret as this is a public space)
Birth place of Tommy Ramone
One of the most famous pop musican with Hungarian relations was Tommy Ramone, the drummer of Ramones. Most Hungarians do not know what the Ramones is or that Tommy was born in downtown Budapest near the Toldi cinema (Bajcsy-Zsilinszky út 36-38).
Doing
- Bath culture. Have thermal bath and different type of sounas in a classic bath
- https://www.szechenyifurdo.hu/ - this is the most classic, but with the most tourists
- https://www.rudasfurdo.hu/ - a bit more hidden and have a very nice view to the river
- https://www.lukacsfurdo.hu - hidden most local
- The bridges - it worth to walk through some of them, they provide a nice view to the city
- Szabadság - This is the best to walk, it is anyways between the Vásárcsarnok and the Gellért square, where the Gellért tér is
- Széchenyi chain bridge - Again between two places worth to check, district V. on the Pert side and the castle district in the Buda side.
- Margit - This is more interesting from architecture point of view as it has a 45 degree curve in the middle of it where it attaches to the Margit island
Generic notes
The city is in the two sides of the river Danube. Buda is the hilly part, usually this is where more wealthy people are living and Pest is the flat part. Public transport is quite good, it is possible to get from anywhere to anywhere within a reasonable time.
The city is safe, it is okay to go almost anywhere at any time. naturally there are dark corners as in any other city. Unfortunately in the last couple of years the Hungarian government promoted a lot homophobia and racism, the affects of these can be recognized in the people also.
Not all Hungarians are speaking English. You can try German, French, Italian, Spain or Russian also.
If you run in to any issues or have any questions feel free to contact me on Slack or on +358-40-three-five-eight-0991.