Masai Mara Safari
From Nairobi, take a matatu / minibus to Narok: Bus Station Map Location: -1.283216, 36.830181 . Try to arrive before 1:30 pm.
In Narok the matatu drop off is at a gas station, Map Location: ???. Walk to the bus station which is only about 500 m. Map Location: ???.
Before 13:00-13:30, take matatu C12 from Narok to the Sekenani gate, Map Location: -1.521854, 35.336830 or any of the other gate where your camp is located.
After 13:30, you can arrange a shared taxi.
Lake Naivasha and Naivasha town
From Nairobi, you can take the matatu bus to Naivasha which is the gateway to three national parks: Lake Naivasha N.P. (boat tours and Crescent Island Game Sanctuary, Hell's Gate N.P. (mountain biking) and Mount Longonot N.P. (crater hike).
The matatus leave frequently from the city center at Map Location: ???.
Lake Naivasha National Park
There are plenty of "boat ride offices" by the lake by the hotels, lodges, campsites, etc. The prices range from 1500 to 3000 kes per person.
Crescent Island is definitely worth a visit. It is one of the few places in Kenya where you can walk amongst the animals (giraffes, zebra, impalas, etc.). It's actually a peninsula so you can also drive to it.
One travel blogger highly recommends taking a trip to Elsamere during your stay – Enjoy !
Hells Gate National Park
From Naivasha, find a taxi or motorbike to take you to the park headquarters and pick you up again.
There are no predators here but plenty of zebras, antelope, buffalo, and giraffes. A guide is not needed.
Mountain bikes are the best way to see the park and can be rented at Elsa Gate or on the main road at the turn-off 2 kms from Elsa Gate (for around 5 USD per day?)
Mount Longonot National Park
Longonot can also be reached from Naivasha.
Longonot has a very easy trail to follow up and an easy trail to follow around the crater rim with no guide.