Well, our time on Santa Cruz was coming to an end.  One more self-guided tour left on our list and then we would be taking a boat to Isla Isabela.
The two places we wanted to go to were the Rancho Primicias (tortoise reserve) and the lava tunnels.  The tortoise reserve's entrance fee was $3.00 each and the entrance cost to the lava tunnels was the same but the day we went to the tunnels there was no admission charge.      When we left Puerto Ayora,the sky was clear but as we approached Santa Rosa the clouds were rolling in.  We wondered if we would be wandering around the turtle reserve in the rain, and would it be safe to go inside the lava tunnels? There was no need to worry however, as luck was on our side and the rain clouds disappeared.
Taxi drivers have a set rate to the various tourist attractions. It cost us a total of $40.00  return for the ride to these two places.  The taxi driver waited for us at both places and then he drove us back to the pier.  The ride each way was approximately one hour.  We thought $40.00 was a good deal considering what you would have to pay back home.
I had read that the taxis on Santa Cruz were pick up trucks and this was true. After being here I understand why that was the case since I had a first-hand visual of the island. The pick-ups are handy if you want to bike,or hike.  Some of the terrain is pretty rough, and some of the bike riding/hiking would be quite a climb.  So, having the pick-up truck aka taxi gave people the option of putting their bikes in the pick-up truck and have the taxi driver take you to the top of let's say that steep climb up the mountain allowing you to bike down.  One time in Puerto Ayora, Tom biked around town and went a few kilometres out.  Tom said it was tough because some of the road is cobblestone which made the ride difficult.     Rancho Primicias is a wildlife reserve, but really it is known for being a tortoise reserve.  I wish I had  picture of this scene, but I don't...so here's my description.  As we were getting closer to the tortoise reserve, the taxi driver had to steer the taxi to the sides of the road because there were tortoises meandering on the middle of the road and when I tell you this I don't mean he had to do this just one or two times, it was several times.
I cannot tell you what it was like to see these tortoises up close.  There was no division between us and them, no walls, or fences.  The rule was that you stay 6 feet away. There were large and medium size tortoises at the reserve.  We were able to hear them breathe even at 6 feet away.  I cannot tell you how awesome that was because who would ever think of hearing tortoises breathe.     We also saw lots of tortoise poop (big deal you say?) and I did take pictures of it because the tortoises eat about 62 varieties of vegetation and when they poop they are re-fertilizing the grounds.  Another example of how fine-tuned mother nature is.
A short distance away were the lava tunnels. The driver told us (mostly through hand gestures) that he would meet us at the other end of the tunnels. The tunnels are underground tunnels about a kilometre in length.  They were formed when the outside skin of the lava solidified.  When the lava flow stopped, the molten lava inside kept on going and emptied out the solidified skin and left the tunnel. (so says the Lonely Planet).  Since the tunnels are on private land we didn't need a guide.  When we first walked into the tunnel, we thought no big deal.  It was lit and we didn't have to crouch, which was a good thing for Tom.  We brought a flashlight, but hardly used it.  Well, first impressions are deceiving.  As we moved deeper into the tunnel, there was less lighting.  Tom did use his flashlight but we both quickly agreed it was probably safer not to use it because as we continued our walk there were more and more broken stones that we had to either walk on (they were slippery), or straddle over.  We felt our concentration needed to be focussed on not slipping rather than worrying about the flashlight, since there was some lighting.  As we went deeper into the tunnel the head space became limited due to number of rocks that were accumulated upwards and as a result decreased our head space. As we continue our walk we ended up being crouched down quite a bit AND THEN, in front of us was a crawl space that we each had to go through.  There was like a burlap bag on the ground so we each shimmied our way through the crawl space.  Tom was doing some positive self-talking to himself and then we could see "the light at the end of the tunnel" (thank goodness).  So as we moved towards the light we realized the way out was by climbing up a very steep set of stairs that were more like a ladder.  Our driver was waiting for us and upon seeing our faces and our gesturing, he laughed. Overall, we were glad that we did the lava tunnels, we would have kicked ourselves if we hadn't.  There was no disputing though, that the tortoise reserve was the highlight of our day!