If Nairobi's prostitutes and the zones where they ply their trade were a secret, then it would probably qualify as Kenya's worst kept secret.
Like hawkers, the prostitutes have a cat-and-mouse relationship with the authorities, with law enforcement officers swooping on them now and again.
But this does not stop the trade from flourishing and the retailers making a living out of it.
Unlike hawkers, though, the prostitutes have not had their issues addressed like having special markets built for them, or as then Local Government minister Karisa Maitha did in 2003, allocated them space in the city's backstreets.
Now imagine for a moment if the City Council of Nairobi was to add to the Sh3 million it collects every day through parking tickets the proceeds from the rent or taxes these women would pay for the zones they operate in.
Well, according to Nairobi Mayor George Aladwa, something along these lines could be in the offing in the foreseeable future if the city council takes a closer look at its by-laws and Kenya's laws on prostitution.
Speaking at a meeting with non-governmental organisations at City Hall on Saturday, Mr Aladwa said the council would want the public to decide on the matter after the by-laws are studied thoroughly.
The mayor said the council would order its askaris, known for the zeal with which they go about their job, to stop harassing prostitutes, who are referred to as commercial sex workers by NGOs.
"Wengi wa wananchi wa Nairobi hawajui sheria ambazo ziko katika baraza kwa hivyo tumekubaliana na wale wanaofanya biashara hiyo, wanaume na wanawake kwa sababu wako kwa hivyo vikundi viwili kwamba watajengewa mahali ambapo wanaweza fanya biashara hiyo, (A lot of Nairobians do not know the city's by-laws.
"We have therefore agreed that those who run that business, both men and women, because we know the trade is across the genders, that we will have a special place allocated for them where they can go about their business)," said Mr Aladwa.
According to the mayor, the prostitutes have in the past complained of harassment and abuse by clients, some of whom approach them in groups of three and bundle them into vehicles.
He said most cases of abuse had been reported by those who operate at the end of Koinange Street, in the vicinity of the Holy Family Minor Basilica and next to Teleposta Towers.
The mayor said the council would offer security to the prostitutes once the laws are harmonised.
Koinange Street has long been associated with prostitution in Nairobi, with the twilight girls taking it over at night when the offices and banks located there have closed for the day and the clubs opened for the night revellers.
Kenyan law is, however, explicit that prostitution is illegal, with Articles 151 to 156 of the Penal Code dedicated to prohibiting the practice in the various ways in which it would manifest itself.
For example, Article 153 provides for the manner in which a man would be found to be in breach of the law if he "knowingly lives wholly or in part on the earnings of prostitution" or "persistently solicits or importunes for immoral purposes" in a public place.
A man would also be guilty of a misdemeanor if he was to "live or to be habitually in the company of a prostitute or is proved to have exercised control, direction or influence over the movements of a prostitute in such a manner as to show that he is aiding, abetting or compelling prostitution."
The law similarly bars women from living on the proceeds of prostitution or controlling another woman for the same purpose.
It is also illegal to own, rent or manage a building that is used as a brothel. Last week, 26 women were arrested for the offence in Parklands and Westlands.
If the City Council fulfils its mayor's agreement with the NGOs, it will join the league of cities in the Netherlands, where prostitution and the operation of brothels is legal and has been regulated since the year 2000.
Nairobi could even have its own version of De Wallen, the largest red-light district in Amsterdam which is an attraction for tourists seeking sex.
There have been concerns there that this tourism is also attracting criminal activity.