If you have been to Halifax, then you have seen the Citadel. The Halifax Citadel is a rather distinguishing feature of the capital of Nova Scotia, in fact it would be safe to say that the existence of the Citadel was the reason for the creation of the municipality known as Halifax. Technically; however, the citadel does not belong to Halifax, it is federal land, specifically a national historic site. Therein, lies the crux of a long simmering dispute between the Halifax Regional Municipality and the Federal Government that is heading to the SCC.

In short, the municipality feels that the feds did not pay enough for the Citadel for an extended period of time and is trying to get the money it feels is owed to it.

Long form: 2010 FCA 196 at para 1:

Lands and property owned by the federal Crown are exempt from provincial and municipal taxation by virtue of section 125 of the Constitution Act, 1867. In order to compensate municipalities for the resulting loss of revenue, the Payments in Lieu of Taxes Act, R.S.C. 1985, c. M-13 (PILT Act or Act), authorizes the Minister of Public Works and Government Services Canada (Minister) to make payments in lieu of the taxes (PILT) that would have been paid to the municipality if the federal property in question had been taxable.

And from the SCC Case Summary:

Administrative law – Judicial review — Municipal law – Taxation – Real property tax – Payments made by Federal Crown in lieu of real property tax — Assessed value of Halifax Citadel — Whether the Federal Court of Appeal erred in holding that the Minister is unconstrained by the assessed value of the property determined by the assessment authority in determining the property value of a federal property for purposes of the PILT Act — Whether the Federal Court of Appeal erred in holding that the Minister acted reasonably in determining the property value of the Halifax Citadel lands (adopting the determination of the Dispute Advisory Panel appointed under the Act), and in particular in valuing the portion of the lands upon which are located improvements which are exempt from payments in lieu of taxes, representing 47 of 49 acres of the site, at $10 – Whether the Court should consider the present case as it raises similar issues as Montréal (City) v. Montréal Port Authority 2010 SCC 14, [2010] 1 S.C.R. 427, but from the perspective of assessed value — Payments in Lieu of Taxes Act, R.S.C. 1985, c. M-13.

In this situation the municipality disagrees with the value that the minister applied to the land to the tune of $12.7 million over a period of roughly 12 years and the case has been argued at various levels with various results over the last 3 years (2009 FC 670, 2008 FC 1159 2008 FC 1034and )and is now going to the SCC .

Ironically, many Nova Scotians and especially Haligonians have had issues with their property assessments skyrocketing in value in recent years and had their applications to appeal the assessment summarily dismissed.